Syntax of the Cases Home PageDative
Syntax of the Cases in the Pali Nikayas
The Instrumental Case
§61. [General Character]
The fundamental use of the inst. in Pāli as in the older languages is to denote the thing with which an action is performed. Hence Brugmann prefers to call this the with-case (‘Mit-Kasus’, KVG §540), because the with-idea may either signify connection or denote the means by which an action is done or something happens. Kaccāyana defines this (viz. karaṇa-kāraka) as “that by which an action is done” ‘yena vā karīyate taṃ karaṇaṃ’ Kac. 290.18 and further lays down the rule that the third case-affix is to be employed to express the karaṇa, ‘karaṇe tatiyā’ Kac. 288.19 while Moggallāna merely states that the third case denotes the agent or the instrument. ‘kattu-karaṇesu tatiyā’ Mog. II.18.20 We may observe in this connection that Indian grammarians are very careful to distinguish the logical function of cases which they call kāraka from the purely grammatical notion of cases. Pāṇinī meets this difficulty in much the same way. He first defines the karaṇa-kāraka as ‘that which is especially auxiliary for the accomplishment of an action’, ‘sādhakatamaṃ karaṇaṃ’ Pāṇ, I.4.42.21 a more comprehensive definition than that of the Pāli grammarian, and then adds the rule that in denoting the agent or the instrument the third affix is to be employed. ‘kartṛkaraṇayo tṛtiyā’ ibid. II.3.18.22 It is interesting to note that Kaccāyana has a separate rule for the agent, ‘kattari ca’ Kac. 290.23 which is syntactically preferable to the others’ treating them together.
Modern grammarians cp. M.W. Smith, Studies in the Syntax of the Gāthās of Zarathushtra, §14.24 regard the inst. of agent as only one aspect of the inst. of means in its widest sense (KVG §554). There is however a fundamental difference both grammatically and logically between the two. The inst. of agent is only applicable with the passive or the causative verb and virtually denotes the subject of the action; it is no mere ‘auxiliary’ as is implied in the designation ‘inst. of means’. All Indian grammarians  regard kartṛ-kāraka and karaṇa-kāraka as quite distinct in their logical functions.
This case seems to have had a varied and confused application even in early I.E., overlapping the uses of other cases, notably the abl. and the dat., and so lost its separate existence in some of those languages. Neither Greek nor Latin has any separate form for this case; in Greek the dat. supplies the want, in Latin the abl. Buckland Green, Notes on Greek and Latin Syntax, §80.25 This may perhaps explain why there is such a confusing similarity between the uses of the abl. and the inst. in Pāli (vide §§73.b,81,122). Speyer has drawn our attention to the fact that though the third case has been styled the instrumental after its most usual employment of expressing the instrument or means or agent, yet its starting point is rather the conception of accompaniment for which reason some call it the sociative. View of Delbrück in his treatise Ablativ, Localis, Instrumentalis.26 “Nor can there be any doubt”, he says, “the suffixes, by which the third case is made, viz., -bhi and -ā convey the meaning of accompaniment, simultaneousness and nearness” (SS §57). In Pāli, however, the inst. alone for the sociative is not very frequent being superseded by the constructions with prepositions like saha and saddhiṃ or sa- in compounds. But in principle even the inst. with such prepositions falls within the sociative class because it signifies the idea of accompaniment, association, concomitancy or mutual relations as the case may be. In addition to these uses saha may denote simultaneousness or even form an adverbial phrase with the substantive in the inst. case (§64), which functions are logically closely related to the idea of accompaniment, though perhaps not so directly as the rest.
§63. Inst. of Association or Accompaniment.
a. This is the sociative use proper; it expresses the person who accompanies the agent with verbs denoting motion and the like (cp. KVG §541). e.g.,
āyasmā Ānando ... Cetakena bhikkhunā pacchā-samaṇena, yena Subhassa ... nivesanaṃ ten’ upasaṅkami D I.205
“the venerable Ānanda ... set out for the residence of Subha ... with the monk Cetaka as attendant  (-recluse)”.
An extension of the same use is frequent in the Nikāyas to denote mutual relations between people:
i. It may express the person who is united with another. e.g.,
mātaraṃ pi puttena samānetā ahosi D III.160
“he was one who joined mother with son”;
missibhāvaṃ gato tayā D II.267 (V.)
“gone to union with thee”.
ii. Similar is the construction with verbs meaning to enter into talk or discussion. e.g.,
kena sākacchaṃ samāpajjati D III.38
“with whom will he enter into conversation?”.
iii. All verbs of conferring, conversing, talking, discussing etc. likewise take a similar inst. e.g.,
Mahā-Govindo brāhmaṇo Brahmunā sākaccheti sallapati manteti D II.237
“the brahmin Mahā-Govinda (Lord High Treasurer) converses, talks and deliberates with Brahmā”;
Ambaṭṭho māṇavo caṅkamanto pi nisinnena Bhagavatā kañci kañci kathaṃ sāraṇīyaṃ vītisāreti D I.90
“the young Ambaṭṭha even while walking up and down conversed on various matters with the Blessed One who was seated”.
b. This same sociative inst. is used to express the thing with which or together with which another is presented and so on. e.g.,
Tena kho pana samayena Aggika-Bhāradvājassa brāhmaṇassa sappinā pāyāso sannihito S I.166
“At that time milk-rice was provided for the brahmin Aggika-Bhāradvāja together with clarified butter”;
sālīnaṃ annaṃ paribhuñjamāno, sakuntamaṃsehi susaṅkatehi Sn 241
“eating food made of (the best) rice with well-dressed fowl”.
The thing thus denoted may express the idea of accompaniment in much the same way as the person who accompanies. e.g.,
Atha kho Bhagavā yathā dhotena pattena Pañcasālaṃ brāhmaṇagāmaṃ piṇḍāya pāvisi S I.114
“Then the Blessed One entered Pañcasālā, the village of the brahmins, for alms with his well-washed bowl (i.e. taking his bowl)”.
The parallel idiom in this case would be the acc. with the gerund ādāya “taking”, which is the prevailing construction in later prose. The gerund ādāya due to this employment came to be regarded as an indeclinable with prepositional force (c. acc.; vide P.T.S. Dict. s.v.).  The same is found used metaphorically in verse, in which case it borders on the inst. of attendant circumstance or characteristic. This is similar to the construction inst. + sampanna which usually appears as compound. e.g.,
nibbiṭṭhena carāmi sabbaloke Sn 25
“with what I have gained I wander about in the world”.
In spite of the various nuances in which this inst. is applied, the fundamental notion underlying all such uses is the same, viz. the sociative idea.
§64. Sociative Inst, with saha, saddhiṃ & sa-.
All these instrumentals can be accompanied by saha, saddhiṃ or sa- “with” which are prepositional adverbs according to Macdonell (VGS §199 B.3. cp. Vedic sahá and sākaṃ). Local grammarians too regard the inst. in such instances as being originally due to the prepositions saha and saddhiṃ. ‘sahâdiyoge ca’ Kac. 289.27 It is however clear from the preceding paragraphs that the inst. alone can be used here without any such help word and that these adverbs were only later introduced probably to avoid syntactical confusion with other instrumentals such as those of means etc. and in certain cases for emphasis and precision. These uses can be illustrated under the various sub-headings of the sociative class, thus:
a. With the inst. of accompaniment and association; e.g.,
mahatā bhikkhu-saṅghena saddhim ... D II.90
“with a great multitude of monks”;
saha rājūbhi D II.258
“with the kings”.
The same construction occurs with sa- in compounds. e.g.,
sadevake loke samārake sabrahmake sassamaṇa-brāhmaṇiyā pajāya sadeva-manussāya D II.12
“in the world of gods and men with its Māra and Brahma, together with its hordes of recluses and brahmins, kings (lit. gods) and men”.
b. With the inst. expressive of mutual relations such as union, conversation, discussion etc.; e.g.,
Bhagavatā saddhiṃ mantayamānassa M I.205
“of him conferring with the Blessed One”;
evaṃ dutiyena saha mam’assa vācâbhilāpo Sn 49
“thus if I shall pass words with another ...”
c. With the inst. expressing simultaneity; eg.,
saha dassanen’ eva A IV.213
“at the mere sight of (lit. with the very sight ...)”;
parinibbute Bhagavati saha parinibbānā (§6). S I.159
“simultaneously with the passing away of the Blessed One”.
d. With the inst. denoting the accompanying circumstances; e.g.,
saha viññāṇena ... D II.64
“with consciousness ...”;
saha dhammena ... D II.104
“with righteousness ...”;
the second example is almost adverbial in employment and can be rendered “righteously” like an adverb of manner. Hence logically it comes to border on the inst. of means.
§65. Inst. of Attendant Circumstances.
Closely related to the above sociative inst. is the inst. used to express the attendant circumstances, that is to say, incidents, conditions, moods, feelings and manifestations that accompany or characterize the agent (cp. KVG §542). These may be broadly classed under the well known designations of manner and quality, parallel to the Latin abl. modi et qualitatis (cp.SS §63.II.31y, & §67). It has to be mentioned here, however, that by the term manner is not implied the purely adverbial function of that case. Perhaps the former is better designated the inst. of description. In Pāli this inst. has an extensive use and in many instances borders, as has been observed in the foregoing paragraph (d.), on the inst. of means (§66), especially in the case of the inst. denoting the posture or mood. It has a logical relation to the absolute uses of the loc. and the gen. (§§182&158) just as some uses of the inst. of means (§68.c.). One can hardly fail to recognize the absolute nature of the inst. in such examples as:
atha kho pāpima āyasmā Vidhuro bhinnena sīsena lohitena gaḷantena Kakusandhaṃ yeva Bhagavantaṃ ... anubandhi M I.337
“then O Evil One the Elder Vidhura, with his head broken and blood oozing, began to follow the Blessed One Kakusandha”.
The following distinctions as to its general application may be noticed: 
a. i. The inst. denoting attendant circumstance or incident in the literal sense is seldom found in the Nikāyas. e.g.,
kharassarena paṇavena rathiyāya rathiyaṃ ... (taṃ) ... parinetvā D III.67
“having led (him) from street to street ... to the accompaniment of the harsh sound of a drum (lit. with a rough-toned drum)”.
ii. It may also denote a continued action which attends upon another (action). e.g.,
kāya nu ’ttha bhikkhave etarahi kathāya sannisinnā D II.1
“with (i.e. engaged in) what kind of talk were you seated (together) just now, O monks?”;
yāya mayaṃ etarahi kathāya sannisinnā D I.178
“engaged in which talk we were seated just now”.
iii. Or it may signify a certain circumstance, such as a mark, sign or injury, temporarily characterising a person. Such, for instance, is the already cited semi-absolute employment. e.g.,
Atha kho bhikkhave Kāḷī dāsī bhinnena sīsena lohitena gaḷantena paṭivissakānaṃ ujjhāpesi M I.126
“Then the maid-servant Kāḷī, with her head broken and blood oozing (therefrom), called to (lit. stirred up) the neighbours”.
This however is not the same as the inst. of characteristic ‘itthambhūtalakṣaṇe’ Pāṇ. II.3.21.28 which is illustrated by Pāṇinī with the example jaṭābhiḥ tāpasaḥ “an ascetic by (the fact of his having) matted hair”, though it signifies a mark or sign characterising a person. This logically falls under the category of cause (§67).
b. Very similar to the above is the inst. used to express physical and mental attributes or manifestations. This may denote either quality (cp. SS §67) as in
mahāpurisalakkhaṇehi samannāgato D II.16
“gifted with the signs of a super-man”,
or manner as in
rājā niyyāsi ... rājānubhāvena D I.49
“the king ... set forth ... in (lit. with) royal splendour”;
cp. Vedic út sūryo jyotiṣā devá eti (KVG §542) “god Sūrya rises with splendour”,
c. It is also used to express conditions of body and mind which attend the agent engaged in an action. e.g.,
rakkhiten’ eva kāyena ... gāmaṃ vā nigamaṃ vā piṇḍāya pavisissāmi S II.271
“with my body guarded shall I enter village or hamlet for alms”;
dissamānena kāyena dhammaṃ desesi S I.156
“he preached the  doctrine with his body visible”;
sucibhūtena attanā viharati
“he lives with his self (Comy. mind) purified”.
ken’ attanā gacchati Brahmalokaṃ Sn 508
“with what body (lit. self) does he go to the Brahma-world?”.
d. The state of mind or mood (cp. KVG §542) in which one acts or exists is also denoted by this inst. e.g.,
aññatarena samādhinā nisinno hoti D II.270
“he is seated in a particular intent state of mind”;
anupādisesāya nibbāna-dhātuyā parinibbuto D II.109,140
“entered Utter Peace in that element of cessation wherein no basis (for rebirth) is left”.
e. It also denotes the posture in which one sits or lies. The parallelism with the Latin abl. modi is here very clear. e.g.,
pallaṅkena nisīdeyya D II.211
“would sit with legs cross-wise”;
dakkhiṇena passena sīhaseyyaṃ kappesi D III.209
“he slept like a lion on his right side”;
ākāse pi pallaṅkena kamati D I.78
“he travels cross-legged in the sky”
(cp. Dial. II.89);
daṇḍo upari vehāsaṃ khitto aggena nipatati S II.l84
“the stick thrown up into the air falls with its top (down)”.
f. The same logical function as denoted by the inst. expressing mood (d.) is implied in a peculiar idiom which is used parallel to the cognate object. e.g.,
santena vata bhante pabbajitā vihārena viharanti D II.130
“those who have gone forth (into the Holy Life), Sir, indeed live in a peaceful manner (lit. dwelling)”; cp. santena nūn’ajja Bhagavā vihārena vihāsîti D II.205.
Out of the inst. of attendant circumstances has developed a peculiar idiom which closely resembles the dat. of purpose (§106), thus providing another instance of case contact. e.g.,
Kosinārakā Mallā santhâgāre sannipatitā kenacid eva karaṇīyena D II.47
“the Mallas of Kusinārā were assembled in the mote hall with some business (at hand)”.
Here the notion of attendant circumstance is quite clear. The idiom appears accordingly to be on the borderline between “with a business” (attendant circumstance) and “for a business” (purpose). Similarly:
Campāyaṃ paṭivasanti kenacid eva karaṇīyena D I.113,150
“they were  living at Campā on some business”;
Virūḷhakassa ... santike kenacid eva karaṇīyena D II.207
“near Virūḷhaka ... for (lit. with) some work”;
The idea of purpose, however, is more marked with verbs of motion: e.g.,
Dasamo gahapati Aṭṭhakanāgaro Pāṭaliputtaṃ anuppatto hoti kenacid eva karaṇīyena M I.349
“the householder Dasama Aṭṭhakanāgara had come to Pāṭaliputta for some business”.
Hence it is not surprising to find the idiom yena atthena employed just like yassa atthāya to denote purpose, though the idea of attendant circumstance is not yet lost in the former. e.g.,
yena atthena ... sannisinnā D II.209
“assembled for which purpose”;
yena atthena devā sannipatitā D II.225
“the gods ... met for which purpose”.
It is also found in the gāthā literature. e.g.,
yen’ atthena idhâgato Sn 430
“come hither for which purpose”.
§66. Instrumental of Means.
In the category of means in its widest sense are included the instrumentals of means (in the ordinary sense), of instrument, of way by which, and even of the agent by some authorities. cp. W.M. Smith, Studies in the Syntax of the Gāthās of Zarathushtra, §14.29 But, as has been already pointed out (§62), the agent is better treated separately by virtue of its ‘independent character’ ‘svatantrya’, as opposed to the other cases which are called ‘paratantrya’ or dependent by Skr. grammarians, especially, Patañjali; cp. Philosophy of Sanskrit Grammar, p. 228.30 in the conception and construction of the sentence. Pāli grammarians too preserve this distinction. Kac. 288 and 290.31 The inst. of means has a varied use in the Nikāyas, extending by stretch of idiom and usage into other established categories. Its most frequent and essentially fundamental application is to express the means or the instrument, in the physical (narrow) sense of the term, by which an action is accomplished. e.g.,
na musalena ... paṭhaviṃ khaṇati M II.51
“he does not ... dig the earth with a tool”;
mahānaṅgalena kasanto S III.155
“tilling with a large plough”;
varattāhi bandhitvā D III.21
“having tied with straps”;
ekena cīvarena naṃ acchādehi D II.133
“cover him with one robe”.
It may be mentioned here that the inst. of means can sometimes border on the inst. of cause or even of relation (§67 & 69), as in the following example where all these nuances seem  to be implied by it:
Mahā-Govindaṃ brāhmaṇaṃ dhanena sikkheyyāma D II.245
“let us gain over the brahmin Mahā-Govinda by means of (through or in point of) money”.
Or sometimes the substantive in the inst. may denote an idea contained in the verb, in which case we have a striking parallel to the cognate use of the acc. (§35). e.g.,
agginā daheyya A I.136
“would burn with fire”.
Here daheyya alone would convey the necessary meaning. This inst. can also be used in abstract manner like the other cases. e.g.,
aminā p’ etaṃ pariyāyena S V.110
“by this method”.
In the following instance the inst. pāṇehi seems to be more like a sociative (gone with their lives) though in a way it can be regarded as denoting the means:
Samaṇaṃ khalu bho Gotamaṃ anekāni deva-sahassāni pāṇehi saraṇaṃ gatāni D I.116
“many thousands of gods gone to the recluse Gotama as refuge with their lives”.
This is used parallel to the frequent phrase yāvajīvaṃ pāṇupetaṃ saraṇaṃ gataṃ M I.368.
a. This same inst. of means is invariably employed in expressing the part of body or limb exercised in accomplishing an action. e.g.,
ubhohi hatthehi udakaṃ omasitvā D II.176
“having touched water with both his hands”;
pāṇinā talaṃ āhacca D II.262
“striking the earth with his hand”;
na sahatthā paṭhaviṃ khaṇati M II.51
“does not dig the earth with his own hand”;
sahatthā santappesi M I.393; A I.274; D I.109; Sn p.107
“fed with his own hand”.
In these examples the particle sa- (in sahatthā) has to be taken as meaning “his own”, corresponding to Skr. sva (vide §6; cp. sadesa “one’s own country” P.T.S. Dict. s.v.), and not as the contracted form of saha “with”, as suggested by Franke (Z.D.M.G. 1892 p.313). For saha + inst. never directly signify the means by which an action is done or the instrument, because saha is only a sociative adverb (vide §64) denoting either accompaniment or attendant circumstance. This is also supported by the fact that sahatthā can stand side by side with the pure inst. of means (instrument) as with musalena “with (by) a tool” in the cited context: na musalena na sahatthā ... M II.51. Moreover the Avestan tā zastā which Franke adduces as a parallel is also the inst. of means, tā being only “his”, the personal pronominal  adjective. cp. M.W. Smith, loc.cit. p. 100 (yasna 43.4 & foot-note).32 Other examples which belong to this class are:
padasā yeva pavattesi D I.107
“caused him to roll with his foot”;
sirasā vandati D II.148
“worships with (bowed) head”;
samehi pādehi patiṭṭhahitvā D II.15
“having stood firm with level feet”;
mukhena eva khādati D III.6
“eats with the mouth”;
Bhagavato pādāni mukhena ca paricumbati M II.120
“he kisses the feet of the Blessed One with his (lit. mouth) lips”.
With certain verbs, such as those meaning “to take, bear, carry”, the inst. is interchangeable with the loc., when the limb or part of the body with or by which such action is done implies at the same time that part at which the carrying etc. is made. Though this optional construction is logically permissible and is actually attested in Indian syntax (SS §74.8), in the Nikāyas the inst. seems to be the popular idiom even here (but cp. §§166.e. & 165.f.). e.g.,
gabbhaṃ kucchinā pariharati M I.266
“she bears the embryo in (lit. with) her womb”;
aññā aṅkena pariharanti D II.19
“others carry (him) about on their hips”;
aṅkena vāhitvā M II.97
“having carried on the hip”;
vāmena hatthena bhiṅkāraṃ gahetvā D II.172; III.63
“having taken the jar with his left hand”.
b. The faculty exercised in feeling and perceiving is similarly denoted by the inst. e.g.,
cakkhunā rūpaṃ disvā D I.70
“having seen an object with the eye”;
kāyena paṭisaṃvedi D II.186
“felt by the body”;
cetasā ceto parivitakkaṃ aññāya D II.36
“having known the thought of the (other’s) mind with his own mind”;
manasā pi no aticarī, kuto pana kāyena D II.176
“she did not behave faithlessly even in mind, how then in body?”
c. It is also used to denote the medium through which one communicates, converses etc. with another,
gāthāhi ajjhabhāsiṃ M I.171; Sn p. 66
“I declared in verses”;
gāthāhi paccabhāsi D II.39
“he said in verse”;
sāruppāhi gāthāhi abhitthavi Sn p. 101
“he lauded in fitting verses”;
sarena viññāpeti D II.202,211
“communicates (lit. convinces) by means of the voice”;
imāhi gāthāhi anumodi D II.208
“gave benediction with these verses”.
The medium or manner by which one’s assent or desire  is conveyed may be a mood or a particular attitude, in which case the construction plainly borders on the inst. of attendant circumstance. e.g.,
adhivāsesi Bhagavā tuṇhībhāvena D I.225; II.180
“the Blessed One acquiesced in silence” or “gave his assent by or with silence”.
The name by which one is addressed is also denoted by this inst. e.g.,
nāmena vā gottena vā āvuso-vādena vā samudācaritabbo D II.154
“should be addressed by name, clan or the appellation of ‘friend’”.
d. Similar is the inst. used to express the means by which, especially the conveyance in which, one travels etc. e.g.,
yāva nāgassa bhūmi nāgena gantvā D I.50; M II.113
“as far as the ground was suitable for the elephant, having gone on (lit. by) the elephant”.
e. It is used with the local sense with words meaning path or door to express the passage by which a moving (exit or entry) takes place or the way by which one goes etc. e.g.,
dakkhiṇena dvārena nikkhamitvā D III.67
“leaving through the southern gate”;
uttarena dvārena nagaraṃ pavisitvā D II.161
“entering the city by the northern gate”;
vātapānena rasmī pavisitvā S I.103
“the rays having entered through the window”.
f. Just as in the case of the inst. of attendant circumstance, (§65.f.) here too we may have an idiom parallel to the cognate object. In most of these instances the inst. and the verb are etymologically related. e.g.,
ovādena ovadati S V.385
“he advises with an advice”;
antevāsâbhisekena abhisittā D II.152
“initiated with the initiation of a co-resident pupil”;
khattiyâbhisekena abhisitto A I.107
“anointed with the anointing of a prince”.
Sometimes however they are not etymologically similar and the inst. is cognate only in meaning. e.g.,
adhunâbhisitto rajjena D II.201
“newly consecrated with kingship”.
g. The inst. of means is also used in a participial sense; that is to say, it can be used parallel to the gerund in -tvā, which itself was originally the inst. sg. of the verbal noun in -tu (VGS §163.2). This is naturally restricted to verbal nouns or substantives with a strong verbal element. e.g.,
nâhaṃ taṃ gamanena  lokassa antaṃ ... patteyyanti vadāmi S I.61
“I do not say that by going (having gone = gantvā) I would reach the end of the world”;
saṃvāsena kho Mahārāja sīlaṃ veditabbam S I.78
“by living together, Great King, should right conduct be ascertained”.
h. The inst. of means can sometimes logically stand for an acc. of the external object. The syntactical difference in such cases is due to the difference in view-point and is idiomatical. e.g.,
maṃ ... paṃsukena okiranti M I.78
“they scatter down soil on me”,
lit. “scatter me down with soil”;
saṃvibhajetha no rajjenâti D II.233
“distribute the kingdom among us”, lit. “.. us with the kingdom”.
Here probably the inst. is due to the influence of the prefix saṃ-.
§67. Instrumental of Cause.
The inst. of cause expresses the reason or motive for an action or an existing condition (KVG §550; VGS §199.3.). This use brings the inst. into close contact with the abl., in view of which Sanskrit grammarians enjoin special rules in certain instances forbidding the employment of the abl. to avoid confusion. “The abl. is forbidden and the inst. is of necessity, if, firstly, the cause or motive be at the same time the agent; secondly, if it be an abstract noun of the feminine gender expressing a quality”. See §72.7 (Rem.) in Speyer’s Sanskrit Syntax where he cites the sūtra of Pāṇinī (II.3.25) ‘vibhāṣā guṇe striyāṃ’.33 In Pāli the confusion is worse confounded by the fact that the old inst. in -ā, which Franke has definitely shown to survive in Pāli (Z.D.M.G. 1892) falls in with the abl. sg. in -ā from Skr. -āt (vide §6). Logically too there is ample scope for the two cases to come into contact (§122).
a. The inst. of cause cannot be strictly separated from the inst. of means (§66.a.) because the idea of means with which an action is performed is not far removed from that of its cause. Indian Grammar, however, makes an important distinction between the two. Here there is an elaborate treatment of hetu and karaṇa. The argument may be summed up in the words of Chakravarti, thus: “The very conception of kāraka is intimately  related to that of cause (kriyānimittaṃ kārakaṃ). By hetu is meant the material cause. In the grammatical conception of hetu, we should remember, there is no room for action: Karaṇa or instrument, defined as a ‘cause associated with an action’ (vyāpāravat kāraṇaṃ karaṇaṃ), is intimately related to action. There is however no essential difference between hetu and karaṇa; it is only the association with action that makes the difference”. Philosophy of Sanskrit Grammar, p. 45.34 It is interesting to see from this discussion how far the ancient grammarians’ conception of syntax tallies with modem scientific notions.
b. Kaccāyana after Pāṇinī lays down the rule that the third case-affix is to be used in the sense of hetu, i.e., cause, reason or motive. ‘hetvatthe ca’ Kac. 291; cf. ‘hetau’ Pāṇ. II.3.23.35 The examples adduced are: annena vasati; vijjāya vasati; sakkārena vasati; dhammena vasati. The last however does not strictly mean “he lives by means of the Law” or “he lives by means of righteousness”, but simply denotes “he lives righteously”, in which case we have here only an adverbial instrumental. Its logical import seems originally to have been the idea of attendant circumstance (vide §65.c, cp. §64.d) rather than one of means.
§68. [Cause and Reason]
a. The commonest use of this inst. is to express the cause for the existence of a thing or for some happening. e.g.,
dānena damena saṃyamena saccavajjena natthi puññaṃ S III.209
“there is no merit in (lit. by reason of) giving, discipline, restraint and truthfulness”;
sakena lābhena attamano S II.198
“he was pleased with his gain”.
It may denote the reason for an action, in which case it almost implies the means though not the actual instrument as pointed out in the preceding paragraph. e.g.,
kāyabalena gacchati M II.137
“goes by reason of his bodily strength”.
But such instances are very rare and in the following it merely signifies the cause: in the sense of by way of. e.g.,
āhārena suddhīti M I.80
“purity by way of food”;
udakena suddhiṃ pacceti S I.182
“desires purity by way of water”;
or in the sense of on account of, due to. e.g.,
sabba-phāliphullā honti akāla-pupphehi D II.137
“in full bloom due to blossoms out of season”;
atthi bhikkhave  aññeva dhammā ... ye Tathāgato pavedeti, yehi Tathāgatassa yathā-bhuccaṃ vaṇṇaṃ sammā vadamāno vadeyyuṃ D I.12
“there are, brethren, other things (doctrines) which the Tathāgata declares on account of which, speaking rightly, people extol the praises of the Tathāgata in keeping with facts”.
It may also denote the disease of which one dies. e.g.,
alasakena kālaṃ karissati D III.7
“will die of diarrhoea”;
ten’ eva ābādhena kālaṃ akāsi S I.150
“he died by that very disease”.
b. When it expresses the motive it is often to be rendered by through or owing to, e.g.,
satthugāravena na puccheyyātha D II.155
“were you not to ask through respect for the Master”;
attano paṭibhānena aññe pesale bhikkhū atimaññeti S I.187
“he slights other amiable monks owing to his intelligence”;
ubhayena vata maṃ so Bhagavā atthena anukampi diṭṭhadhammikena c’ eva samparāyikena cā ti S I.82
“considering both points of advantage (lit. through both motives) the Blessed One pitied me, for my benefit in this very life and also hereafter”.
c. This same use is extended to express quite another turn of idiom, which Macdonell calls the inst. of accordance (VGS §199 1.6), meaning for the sake of or on behalf of etc. e.g.,
bhavantānaṃ vacanena gamissāmi M II.148
“ I shall go in accordance with your word (i.e. at your bidding)”;
mama vacanena ... Moliyaphaggunaṃ bhikkhuṃ āmantehi M I.123
“call the monk M. in my name”
(cp. D II.143);
mama vacanena samaṇaṃ Ānandaṃ appābādhaṃ ... phāsuvihāraṃ puccha D I.204
“on my behalf inquire of the recluse Ānanda as to his health and convenience”.
d. There are a few instances where the inst., though categorically coming under the causal group, still, by the peculiar viewpoint obtained in the idiom, approximates to an absolute use. Speyer mentions a similar inst. in Skr. (just as in Latin) which he calls the semi-absolute construction. He says that in all of them the loc. might have been used, corresponding to the Latin abl. absolute (SS §372). Here the inst. represents the action, expressed by the participle, as the cause, or motive, or means  of the main action. e.g.,
evaṃ hi so bhante kakkaṭako sabbehi aḷehi saṃchinnehi ... abhabbo taṃ pokkharaṇiṃ puna otarituṃ S I.123
“thus, Sir, (owing to the fact of) his limbs being broken ... the crab is unable to go back into the pond”;
so rūḷhena vanena saṃchavinā n’eva maraṇaṃ vā nigaccheyya na maraṇamattaṃ vā dukkhaṃ M II.259
“with the closing up and healing of his wound, he neither dies nor comes to deadly woe”
(cp. Dial. Vol. IV. Part II. p.149).
§69. Instrumental of Relation.
The inst. of relation has also been called the inst. of the point because it expresses the point in which a term is applied. Perhaps the designation inst. of specification is the more appropriate term (vide KVG §551). This inst. resembles very closely the inst. of manner, in a logical sense, and in many cases overlaps the uses of the inst. of cause. In fact it is justifiable to regard it as a division of the latter. Macdonell calls this use inter alia the inst. of accordance (VGS §199.1.b) because it denotes that according to which some other thing or person is named or distinguished. Pāṇinī says that “any mark, or attribute, by which is indicated the existence of a particular state or condition is denoted by the third case”. ‘itthambhūtalakṣaṇe’ Pāṇ. 184.108.40.206 Moggallāna has merely followed the Sanskrit grammarian. ‘lakkhaṇe’ Mog. II.20.37 Kaccāyana has the rule that “the third case-affix is to be employed in qualification ‘visesane ca’ Kac. 294; also ‘yen’ aṅgavikāro’ 293.38 and the vutti illustrates it by the examples: gottena Gotamo “Gotama by clan” and tapasā uttamo “best in asceticism”.
§70. The Inst. of Relation may express:
a. i. that by which (in accordance with or in point of which) some person or thing is qualified. e.g.,
Vipassi bhikkhave Bhagavā khattiyo jātiyā ahosi D II.2
“the Blessed One Vipassi, brethren, was a prince by birth”;
Koṇḍañño gottena ahosi D II.3
“was (known as) Koṇḍañña according to his clan”.
This is frequent in gāthā literature also. e.g.,
Ādiccā nāma gottena Sākiyā nāma jātiyā Sn 423
“according to clan called Ādiccas  and according to birth Sākyans”;
kammanā vasalo hoti Sn 146
“becomes a slave according to one’s deeds”.
A few of these instrumentals are inherited from the older language as adverbs. e.g.,
pakatiyā sīlavatī D II.12; M II.99
“by nature virtuous”.
The adverbial implication makes it border on the inst. of manner or means.
ii. The above uses depend on nouns (substantive or adjective) and are therefore adnominal uses. Similarly we may have adverbal uses where the inst. of relation qualifies the action denoted by the verb. e.g.,
sīlena vaḍḍheyyuṃ D III.164
“they would increase in virtue”;
abhivadanti aṭṭhādasahi vatthūhi D I.13
“accuse in point of eighteen matters”.
It may occur also with participles (potential or passive), in which case it closely resembles the inst. of means. e.g.,
iminā dutiyena ṭhānena navā bhikkhū gārayhā bhavanti M I.14
“in view of this (or by means of this) second point new disciples (lit. monks) become censurable”;
anupakuṭṭho jātivādena Sn. p.115
“unreproached in point of birth”;
aniñjamāno kāyena M I.94
“unmoving in (point of) body”;
kāyena saṃvuto D I.60
“restrained in (or with regard to) body”;
vācāya saṃvuto M I.93
“restrained in speech”;
on the last two examples compare Kac. 317.
b. The point in which a comparison is made. e.g.,
ye keci Soṇa samaṇā vā brāhmaṇā vā aniccena rūpena dukkhena vipariṇāma-dhammena seyyo ’haṃ asmî ti samanupassanti (also with sadiso and hīno) S III.48
“whatever recluses and brahmins, Soṇa, regard themselves superior in point of (this) impermanent body subject to grief and change”;
tesaṃ aggaṃ akkhāyati yadidaṃ mahantattena M I.184
“is deemed the highest of them, that is to say, in point of grandeur”.
c. The standard by which multiplicity etc. is reckoned or the dimension in which extent is measured. e.g.,
tena māsena dvādasamāsiyo saṃvaccharo A I.214
“a year consisting of twelve months in terms of that month”;
ekûnatiṃso vayasā D II.115
“twenty-nine years (in point) of age”;
dvādasayojanāni āyāmena D II.146,170
“twelve leagues in length”;
sattayojanāni vitthārena D II.170
“seven leagues in width”.
§71. Inst. in Special Connection with Verbs.
Most of the uses of the inst. described above are found with particular classes of verbs (KVG §546), and, since without the inst. such verbs generally appear incomplete in meaning the former is said to be ‘governed’ by the latter (cp. VGS §199). That particular distinction in sense by virtue of which the inst. is ‘governed’ is brought in the case of many verbs by the prefix saṃ- “co-”. But it cannot be maintained in all instances that the inst. is solely due to the prefix, for, as already remarked in the case of the acc. (§37), the case is not directly due to the prefix but the verb; the prefix only emphasizes the direction or the particular kind of action denoted by the verb.
a. The inst. taken by the great majority of verbs come within the means-group (in the wider sense; cp. KVG §546.2.). Such are verbs expressing enjoyment and satisfaction. e.g., nandati “delights in”;
abhavena assa na nandati D III.187
“he does not delight in his ruin”;
nandati puttehi puttimā Sn 33
“he who has sons, delights in sons”.
The opposite of nandati, viz. socati, admits of the same construction since logically the connection indicated is the same. So we have in the next verse in the Sutta-Nipāta:
socati puttehi puttimā Sn 34
“he who has sons grieves at sons”;
tussati “is satisfied”: e.g.,
santuṭṭho hoti kāyaparihārikena cīvarena D I.71; M I.268
“he is satisfied with a robe to wear on the body”;
santussamāno itarîtarena Sn 42
“being content with this or that”;
“rejoice at, delight in”:
ramati nacca-gītehi D III.197 (V.)
“he delights in dance and song”;
here the loc. is the concurrent idiom (§177.b.) as the rendering “delight in” implies;
abhirama Tissa ahaṃ The nom. form for the gen. mama (?) .39 ovādena ahaṃ anuggahena ahaṃ anusāsaniyâti S III.109
“rejoice Tissa, rejoice at my advice, at my favour, at my admonition”;
santappeti “satisfies, pleases”:
khādanīyena bhojanīyena santappayitvā D I.109
“having treated (lit. satisfied) ... with hard and soft food”.
b. Similar is the use with verbs expressing repletion like pūreti “fills” and pharati “be congested with”. e.g.,
pattaṃ odanena  pūretvā S I.174
“having filled the bowl with rice”;
ayaṃ Jambudīpo ... phuṭo bhavissati manussehi D III.75
“this land of Jambudīpa ... will be filled with people”.
In such instances the gen. can be employed instead of the inst. (vide inst.-like gen.§149). In a way similar to that discussed above (a.), the opposite idea of deficiency or emptiness can also be denoted by the inst. or the gen. (§85).
c. With verbs expressing purchase, exchange and bartering such as kiṇāti “buys”, dadāti “gives for” and icchati “expect for”: e.g.,
hiraññena kayakkayaṃ Kh p.6 (V.)
“bartering in gold”
lit. “buying and selling in gold”;
Dehi je Ambapāli etaṃ bhattaṃ satasahassena D II.96
“Come now, Ambapāli, give this (invitation for a) meal for a hundred thousand (gold-pieces)”;
appena bahuṃ icchati D III.186
“for a little he expects much”.
d. Verbs expressing subsistence, sustenance, or means of livelihood such as jīvati “live by or on”, yāpeti “subsist on”, vasanti, lit. “dwell” but by stretch of meaning “live on” found only in verse: e.g.,
micchâjīvena jīvikaṃ kappenti D I.9
“make a living by (means of) wrong livelihood”;
puthusippena jīvati Sn 613
“lives by different arts”;
yena sippaṭṭhānena jīvikaṃ kappenti M I.85
“by whatever craft they make a living”;
yāva-jīvaṃ surā-maṃsena eva yāpeyyaṃ D III.9
“I would subsist on liquor and flesh till life lasts”;
ekissā pi dattiyā yāpeti D I.166,179; S II.142
“keeps going on a single offering (of food a day)”;
kolehi yāpema M I.80
“let us sustain ourselves with beans”;
vasī Godāvarīkūle uñchena ca phalena ca Sn 977
“lived on gleanings and fruits on the bank of the Godāvarī”.
e. Verbs expressing the thing with which one plays or sports such as dibbati and kīḷati: e.g., akkhehi dibbanti M II.106; D II.312 “play at (lit. with) dice”;
yāni tāni kumārakānaṃ kīḷāpanakāni tehi kīḷati M I.266
“sports with whatever are toys for children”.
This inst. of means is to be distinguished from the sociative use of the same case expressing the person with whom one plays or sports. Still, as may be seen from the above examples, the two conceptions are logically related however slight the connection may be. 
With some other verbs the application falls under the inst. of cause discussed above (§67). It is as much related to the inst. of means as the independent use is to the same. It is generally found:
a. With verbs expressing disgust, repulsion etc. such as aṭṭīyati “be incommoded with, worried at”, harāyati “be ashamed of”, jigucchati “be disgusted at or with”. This use brings the inst. into contact with the abl., gen., acc. and even the loc., for in Skr. jugupsate “to shrink from, shun, or despise” could be used with the abl. or the inst. as found in the archaic literature, and in the later works even with the acc. (vide SS §97 R). The similar verb nibbindati occurs in the Nikāyas with the loc. and the gen. (§166.d.ii). The inst. seems to be the most frequent case with such verbs. e.g.,
iddhipāṭihāriyena aṭṭiyāmi harāyāmi jigucchāmi D I.213; M III.300
“I am disgusted of, ashamed of and loathesome of displays of supernormal powers”;
ahaṃ pi brāhmaṇa jigucchāmi kāyaduccaritena A IV.174
“I too, brahmin, am loathesome of evil conduct in body”.
The Comy. interprets the inst. in the passage jigucchati kammehi pāpakehi Sn 215, which may be either abl. or inst., by the acc. (muttagataṃ viya jigucchati, Pj. II. p.266).
b. With verbs meaning to be offended with, be busy with and be born of such as abhisajjati etc. e.g.,
imāya appamattāya abhisajjituṃ D I.91
“to be offended with or at a trifle like this”;
kehici kehici kicca-karaṇīyehi vyāvaṭo D II.270
“engaged in (busy with) various duties”;
vande te pitaraṃ ... yena jātā ’si kalyāṇī D II.265 (V).
“I adore your father, ... O beautiful one, of whom you were born”.
With another class of verbs the inst. is used to denote association. Such instances belong to the sociative group (§63). This is mostly found:
a. With verbs expressing union and the like, which normally have the prefix saṃ- such as samāgacchati “come together, collide” and saṃsandati “join with” etc. e.g.,
na pi sakaṭena samāgacchāmi  S V.369
“nor do I collide with a carriage”;
Gaṅgodakaṃ Yamunodakena saṃsandati D II.223
“the waters of the Ganges join with the waters of the Yamunā”.
A similar inst. is found in the peculiar idiom
etena p’ etaṃ nakkhamati D II.67
“this does not tally with that”.
b. With verbs having the sense of contending, competing, contesting, fighting and quarrelling such as saṅgāmeti, vivadati, viggaṇhati etc. e.g.,
asurā devehi saṅgāmesuṃ A IV.433
“the demons fought with the gods”;
yadāpi āsi asurehi saṅgāmo Sn 681
“when the battle with the demons took place”;
mātā pi puttena vivadati M II.120
“the mother quarrels with her son”;
rājā rājūhi vivadanti M I.120
“rulers contend with rulers”;
na kenaci loke viggayha M I.108
“at strife with no one in the world”;
ahaṃ pi ñāṇavādo kho pana ñāṇavādena arahati ... iddhi-pāṭihāriyaṃ dassetuṃ D III.12
“I am also a professor of supreme knowledge, and (as such) am indeed fit to display (in competition) my supernormal powers with another one who professes supreme knowledge”.
c. With verbs expressing separation. Here the abl. is the more logical construction (§126) but the use of the inst. is due to the psychological fact that underlying both union and separation there is the notion of mutuality. “Delbr. I.l. p. 71 ‘Der begriff trennung ist zwar logisch der gegensatz von zusammensein, liegt ihm aber deshalb psychologisch sehr nahe’. Or to speak more correctly, it is not the conception of separation that is expressed or signified by the inst., but the notion of mutuality underlying both union and separation find in its adequate expression”. Speyer SS p. 46 f.n.40 e.g.,
sumuttā mayaṃ tena mahāsamaṇena D II.162
“we are completely free from that great recluse”;
maraṇadhammā sattā maraṇena parimuccanti S I.88; V.3
“beings subject to death are released from death”.
In fact the inst. and the abl. occur co-ordinately in the same context. e.g.,
na parimuccanti jātiyā jarāmaraṇena ... na parimuccanti dukkhasmā ti vadāmi S I.24
“I declare he is not free from birth, decay and death”.
Similar parallel employment is found even in the older language (vide SS p.47,f.n.).
§74. Instrumental as Adverb.
Many instrumentals, mostly of the sociative, means, causal, local and temporal classes, having more or less the character of adverbs (SS §77), have come to be applied in a purely adverbial  sense in the Nikāyas. These may be the inst. sg. of nouns, pronouns including numerals, adjectives usually of the positive degree, or of compound formations. Beside the numerous instances where the case-connection (or inflexion) appears to be normal, there is a group of older inherited inst. forms, mainly Vedic in -ā, of which already in the Ṛg-Veda the adverbial use is indicated not only by the sense but by a shift of the accent (VGS §198.6), and which have come to be regarded by local grammarians as mere particles or indeclinables (nipāta-mattaṃ). Such are, for instance, micchā, inst sg. of mithu found as mithuy in the Vedas and mithy in the Brāhmaṇas and divā inst. sg. of dyú found as dívā with shift of accent in the Vedas (VGS p.85, f.n.l ;cp. §2 here). This adverbial use of the inst. being in most cases parallel to that of the acc. (§§47-52), it furnishes another striking instance of contact between the two cases. This is generally found in the case of modal, local and temporal adverbs formed from them.
§75. [Instances of Adverbial Usage]
The uses may be classified in the following manner with respect to their logical functions:
a. Some of these adverbs go back to the inst. of means and are therefore modal in character. e.g.,
manasā pi no aticarī D II.176 cp. M III.179; Sn 1024
“she did not transgress even mentally”;
api ca me satthā pariciṇṇo dīgharattaṃ manāpena no amanāpena S IV.57
“however the Master has been worshipped by me during all this time willingly, not unwillingly”;
pharusenâpi vuccamāno A I.284
“being spoken to harshly”;
saṅkhittena bhāsitassa evaṃ vitthārena atthaṃ ājānāmi D II.281
“of that which has been concisely stated I know the meaning extensively (in detail)”;
cp. the inst. vitthārena, occurring also at D III.241; S IV.92; A II.77,177,189, with abl. vitthārato having similar adv. sense, found in later works (vide P.T.S. Dict. s.v.);
somanassaṃ ... duvidhena vadāmi D II.278
“I describe happy-mindedness two-foldly”,
where the inst. stands for the usual idiom duvidhaṃ katvā; cp. adverbs from other adjectival formations mostly occurring in the gāthā literature: virūparūpena 
mathenti cittaṃ Sn 50
“agitate the mind diversely (under their different aspects)”;
anekapariyāyena pakāsito Sn 15
b. There is a smaller class of adverbial instrumentals denoting “in accordance with”. They do not connote any instrumental sense, as Macdonell has pointed out (VGS §199.1.b), but more or less border on the relative use of the inst. and possibly also on the sociative in the narrower sense of attendant circumstance. e.g.,
atthe panāyati ñāyena D II.21
“he settles the cases legally”
(i.e. according to justice);
dhammena bhoge pariyesāmi Sn p.87
“righteously I pursue wealth”;
ete te Kassapa ubho ante anupagamma majjhena Tathāgato dhammaṃ deseti S I.20
“the Tathāgata, Kassapa, without going into either of the extremes preaches the Law medially (i.e. according to the middle way)”.
We have already mentioned the example
pakatiyā sīlavatī D II.12; M II.99
“naturally (by nature) virtuous”
(§70) where the inst. clearly denotes relation but borders on the adverbial use at the same time (cp. VGS §199.1).
c. The inst. of attendant circumstance proper may itself appear in the role of an adverb, thus: e.g.,
bandhanā mucceyya sotthinā avyayena D I.72
“he would be released from bondage easily and without expense”;
cp. sotthinā “safely, prosperously D I.96; II.346; M I.135; A IV.126; cp. sukhena Th 1.220, “happily” or “safely”, parallel to the adverbial use of the acc. in sukhaṃ seti S I.41; A I.136 and sukhaṃ viharati A I.96; III.3;
kicchena me adhigataṃ D II.36
“acquired by me with difficulty”;
cp. Skr. kṛcchrena (SS §77) as adverb;
kasirena ghāsacchādo labhati D I.251; M I.104; A I.107; S I.94
“one finds food and clothing with difficulty”.
To this class also belong the old inst. adverbs of the type of micchā Sn 438,815 “falsely” (vide §74) and uccā (P.T.S. Dict. s.v.) “high”.
d. The inst. sg. of neuter pronouns is extensively used as adverb mostly in the sense of reason. e.g.,
tena hi samma Ghaṭikāra muñca, gamissāmâ ti M II.48
“therefore friend Ghaṭikāra, let me off, we shall go”.
This is usually found followed by hi with  verbs such as suṇohi and suṇātha, as for instance at D I.62; II.2; Sn p.21, and, as Buddhaghosa remarks, (‘uyyojanatthe nipāto’ Sum. I. p.171), it has an exclamatory significance. The relative pronoun yena is mostly employed as connective corresponding to the acc. yaṃ already dealt with (§50.c). e.g.,
appamattakaṃ etaṃ ... yena puthujjano Tathāgatassa vaṇṇaṃ vadamāno vadeyya D I.3
“this is just insignificant ... that (lit. whereby) a man of the world may say extolling the praises of the Tathāgata ...”;
ko nu kho bhante hetu ko paccayo yena mātugāmo n’ eva sabhāya nisīdati A II.82
“what is the reason, Sir, what is the cause whereby a woman neither sits in the assembly ...”.
The inst. sg. of the interrogative neuter pronoun forms a corresponding adverb with the sense of “how?”. e.g., (gāthā)
sorataṃ kena kathañca dantaṃ āhu Sn 513
“how may they call him compassionate and how subdued?”.
The form etena is once found with a sense similar to that of the connective yena. e.g.,
yadeva ... pītigataṃ cetaso ubbilāvitattaṃ etena etaṃ oḷārikaṃ akkhāyati D I.37
“inasmuch as ... (it consists of) joy and elation of mind, (thereby) is this called gross”.
e. Instrumentals with local and temporal sense may appear as adverbs of place and time respectively (cp. VGS §199.4&5).
i. Local sense: e.g.,
antarena yamaka-sālānaṃ D II.134,137,169
“between the pair of sal trees”;
cp. Vedic adv. ántarena “within” (VGS §198.6). The majority of these are regional adverbs, being instrumentals of nouns denoting the cardinal points. e.g.,
puratthimo vāto pacchimena saṃhareyya S V.444
“the easterly wind would carry (it) westward”;
puratthimena nagarassa navaṃ santhāgāraṃ kārāpetvā M I.343
“having caused a new mote hall to be built to the east of (lit. eastward of) the city”;
pacchimena ca puratthimena ca dvādasa yojanāni ahosi āyāmena D II.146,170
“was twelve leagues in breadth on the west and on the east”;
uttarena Manasākaṭassa D I.235
“northward of Manasākaṭa”.
Adverbs of similar import are formed from the relative and demonstrative pronouns, viz., yena and tena, frequently occurring in the coordinate construction “yena ... tena ...”which is discussed elsewhere (inst. of place §80.b). 
ii. Temporal sense: e.g.,
adhunā kālakato M II.243
ādiken’ eva na byākāsi M II.213
“... did not explain at the very start”; literally it would imply “initially”,
in which case the modal character of these local and temporal adverbs is made clear. There is an elliptical use (?) of the inst. sg. of the demonstrative neuter pronoun, viz. tena, meaning “then”, possibly standing for tena samayena. e.g.,
tena kho pana bhante ahesuṃ ... D II.203
“then, Sir, there were ...”.
On the analogy of these uses we may regard kālena in the following examples as an inst. of time employed adverbially:
kālena gamanaṃ S V.78
“going at the (proper) time”;
lit. “seasonably”; cp.
kālena dhammasavanaṃ Sn 265
“listening to the Doctrine at the proper time”;
akālena M III.48
“at the wrong time (lit. unseasonably)”;
nidhānavatiṃ vācaṃ bhāsitā kālena D I.64; III.106
“speaking (well-) grounded speech (i.e. words) at the proper time (lit. duly)”.
A similar use of a time denoting word is samayena found only in verse. e.g.,
samayena laddhā Sn 388
“obtained in time”.
A few archaic instrumentals also belong to this group. e.g.,
divā ca rattī ca D II.147
“by day and by night”.
On the analogy of divā we are inclined to take rattī too as a Vedic inst. sg. of -ī nouns, analogous to śúcī (inst. sg. vide VGS p.80 & f.n.2). The reading in other places is, however, with the acc. rattiṃ (§2) or the archaic loc. ratto (§2).
f. There is one adverb of quantity formed from the compound stem yebhuyya-, corresponding to Skr. yadbhūyas, ye being the eastern pronominal form (§10). e.g.,
yebhuyyena D I.17,105; II.48
“mostly, for the most part (> usually)”;
cp. Skr. prāyena “mostly”, adverb of quantity. In the following we have the inst. sg. of an avyayībhāva compound used as an adverb denoting manner:
anupubbena parikkhayaṃ gacchati M II.67
Another similar inst. adverb from an irregular stem is sabbatthatāya D I.251; II.187; M I.38, A III.225 “on the whole”, which, as the v.l. sabbattatāya suggests, corresponds to Skr. sarvātmanā (>sarvātmatāya); vide SS. §77. 
§76. Instrumental of Time.
The temporal use of the inst. in Pāli has brought it into contact with many other cases, especially the acc. through the idea of extension and the loc. through the idea of time at which (KVG §545.b., SS §78, VGS §199.5). This latter construction is supposed by Speyer to be a peculiarity of Pāli and Jaina Prk. He suggests that in both these uses of the inst. the fundamental conception is that of concomitancy (SS §78).
The local grammarians too were aware of these divisions of the inst. in the temporal sense. Pāṇinī lays down the aphorism ‘apavarge tṛtiyā’ Pāṇ II.3.6.41 that the third case-affix is to be employed after words denoting the duration of time and space when the accomplishment of the desired object is to be meant. e.g.,
“he learnt the anuvāka in a month”.
It is, however, significant of Kaccāyana’s method of paying more particular attention to the exceptional usages, mostly idioms that do not occur in Skr. but only in ‘Māgadhī’, that he lays down no rule parallel to the above but provides for the quite unexpected turn of expression illustrated by tena kālena etc. with the observation that the inst. is used also in the sense of the loc.. ‘sattamyatthe ca’ Kac. 292.42
§77. [Inst. of Duration]
a. Fundamentally, this inst. expresses the time throughout, during, within or for which an action extends. Since it denotes duration as much as the acc. Brugmann calls it the prosecutive inst. expressive, in this case, of extent in time (KVG §545.b). e.g.,
mayā anupapannapubbā iminā dīghena addhunā M I.82
“not already found by me during all this long period”;
iminā dīghena addhunā sandhāvitaṃ S II.179
“coursed through all this long period”;
imehi kho pana te bhante tiṃsamattehi vassehi atthi koci viseso adhigato ... S IV.300
“has any distinction ... been acquired by you, Sir, during these thirty years?”;
sakkā divasâvasesena gantunti M II.119
“can be gone in the remaining part of the day”.
Mention must be made of the prosecutive inst. denoting time through which found in the stereotyped adverbial phrase kālena kālaṃ which corresponds to the idiom “from (abl.) time to time”. e.g.,
devo ca kālena kālaṃ sammā-dhāraṃ  anuppaveccheyya D I.47 (cp. M I.277)
“from time to time the heavens will send forth bountiful showers”;
kālena kālaṃ manasikātabbāni M I.119
“should be pondered over from time to time (> time after time, i.e. continually)”.
b. Not rarely the above conception of time within which coincides with that of the time after which (cp. SS §78) or before which something is happening.
i. Time after which: e.g.,
Saṃvāsena kho Mahā-rāja sīlaṃ veditabbaṃ, tañ ca kho dīghena addhunā na ittaraṃ S I.78
“Great King, right conduct can be known only by living together and that too after a long time, not by little (short) time”.
This same nuance is expressed by the periphrasis accayena following the gen. of the time denoting word. e.g.,
channaṃ māsānaṃ accayena saṅgāmo bhavissati A I.111
“After six months (lit. on the lapse of ...) there will be a war”;
cp. D II.140.
ii. Similarly the inst. may denote the time by which or before which an action is terminated, or up to which point continuity is implied. e.g.,
etena upāyena paṭhamen’ eva yāmena Kosinārake Malle Bhagavantaṃ vandāpesi D II.148
“in this manner by (or before the end of) the first watch of the night he had made the Mallas of Kusinārā pay their respects to the Blessed One”.
The periphrasis spoken of above is used instead of this inst. also, e.g.,
tassā rattiyā accayena ... paṇītaṃ khādanīyaṃ bhojanīyaṃ paṭiyādāpetvā D II.97,127
“before the passing of that night ... having prepared excellent food both hard and soft”.
§78. Inst. of Time When.
Sometimes however the idea of extension or duration is not so apparent (cp. VGS §199.5), in which case the inst. assumes a syntactical function similar to that of the loc. of time. This is what Kaccāyana means when he says that “the inst. is used also in the sense of the loc.” (§76). As has been already referred to, the fundamental conception underlying this idiom is according to Speyer (SS §78) that of concomitancy. The fact, however, is open to criticism since the same claim can be made  for the adverbial use of the inst. (§75). The logical connection between such adverbial phrases as divā ca rattī ca, adhunā and ādiken’ eva and the inst. of time in tena samayena cannot be denied especially when the adv. kālena “at the right time, seasonably” seems to establish an intermediate link in the psychological development of the idiom. This is also supported by the fact that in Skr. there is no general use of the inst. parallel to the loc. of time, whereas its adverbial use is quite common (SS §77), but that it is widely used in later dialects like Pāli and Prk. Probably, therefore, this is an idiom of popular origin, evolved under the influence of such Vedic usages as ṛtúnā and ṛtúbhiḥ “in due season” (VGS §199.5). Incidentally, this is a further proof for Franke’s argument that Pāli and Skr. cannot have grown in the same region and that the former is derived from a Vedic dialect isolated for centuries from the group that produced (classical) Skr. (Z.D.M.G. 1892, p.315).
§79. [Inst. of Time When]
The most frequent employment of the inst. of time when or at which is found in the stereotyped phrase tena kho pana samayena. This however has not still completely lost the sense of duration, for, as context permits, it may be sometimes rendered “during that time”. e.g.,
tena kho pana samayena āyasmā Nāgito Bhagavato upaṭṭhāko hoti D I.150
“during that time the venerable Nāgita was the attendant on the Blessed One”.
But the translation “at that time” can also be concurrently, and in some cases even preferably, used. e.g.,
tena kho pana samayena Bhagavā divāvihāragato hoti paṭisallīno S I.146
“at the time (or during that time) the Blessed One had gone to spend the midday in solitude”;
tena kho pana samayena rājā ... nisinno hoti D I.47
“at that time the king ... was seated”.
It is significant of these examples that the narrative present hoti itself implies continuity of action, and so the inst. can hardly be said to have lost its original sense of duration.
a. It is interesting to find, however, that Buddhaghosa looks at the problem from quite a different angle. Commenting on tena samayena he says, probably echoing an earlier tradition,  that in the Vinaya texts it is used to signify cause or reason because the inst. here represents the time as the occasion for the Master to formulate any precept. ‘Vinaye pana hetu-attho karaṇattho ca sambhavati ... tena samayena hetubhūtena karaṇabhūtena ca sikkhāpadāni paññāpayanto sikkhāpadapaññattihetuṃ ca avekkhamāno Bhagavā tattha tattha vihāsi. Tasmā tadatthajotanatthaṃ tattha karaṇavacanena niddeso kato’. Papañcasūdanī I. p. 9.43 He makes the same observation on tena kho pana samayena Sn p.13, viz. “it has been said (vuttaṃ hoti) that the inst. is used because that specific moment was taken as the means (opportunity)”. ‘tena samayena karaṇabhūtenâti vuttaṃ hoti’ Pj.II. p. l37.44 This clearly shows that he is representing an earlier tradition whereby all the different uses of the inst. were supposed to be connected to its fundamental notion of means.
b. Another idiom expressing an indefinite point in time, where the idea of extension is hardly found, is aparena samayena “at another time, later on”. e.g.,
So aparena samayena tamhā ābādhā mucceyya D I.72
“Sometime after he would be relieved of that ailment”;
So aparena samayena pabbajeyya D I.60
“later on he would wander forth (into homelessness)”.
c. Similar uses are found in the following where the space of time is so small that the idea of within or during is almost lost. They are very much like adverbs. e.g.,
tena khaṇena tena muhuttena yāva brahmalokā saddo abbhuggacchati A IV.120
“that very moment (simultaneously) the sound rose up as far as the world of Brahmas”;
te ekena khaṇena ekena muhuttena ekamaṃsakhalaṃ – ekamaṃsapuñjaṃ karissāmi M I.377
“in a moment, in a second, I shall reduce you to a mash, a heap of flesh”.
Again, a subtle variation of meaning is found in
ekāhen’eva ... pakkamiṃsu D I.48
“they went away at one and the same day ...”
(cp. SS §78 R.l. Skr. ekāhnā “at one and the same day”).
§80. Instrumental of Place.
This corresponds logically to the above-described inst. of time. Some of these instrumentals have come to be regarded as adverbs. Most of them, however, still retain their independent character. A few of these imply direction or route by which and others are instrumentals with pure local sense, parallel to the loc. of place, just as the inst. of time is used for the temporal loc.. Still others approximate to a prosecutive inst. of the local  variety denoting the stretch of space through which an action progresses. Such is the inst. found in idioms like vanena vanaṃ which originally meant “through forest to forest”. It is only later that this came to be regarded, probably due to the confusion of the ending -ā, as an inst. used for the abl. Of course the same can occur with the abl. instead of the inst. because psychologically “through one forest to another” is the same thing as “from one forest to another”. The idea through which can also be expressed by the loc. (§164).
§81. [Prosecutive Inst. of Place]
a. The prosecutive sense is most clearly expressed by the following examples where the inst. stands parallel to the abl. e.g.,
vanena vanaṃ gahanena gahanaṃ papatati M I.79
“gallops from (lit. through) forest to forest and thicket to thicket”;
rathiyāya rathiyaṃ siṅghāṭakena siṅghāṭakaṃ (parinetvā) M II.108; D III.67
“having led him from (along) street to street and junction to junction”;
but in the following the inst. borders on the idea of means and implies way by which as much as that through which: mā ekena (maggena)
dve agamittha D II.45
“let not two go along the same route”;
titthena eva gāvo pātaresi M I.226
“caused the cows to cross (the river) at or by (lit. through) the ford”.
(cp. KVG §545.a)
b. To this class also belongs the adverbial use of the inst. sg. of pronouns, mostly yena, tena, aññena and ekena, where the local sense is expressed either as direction or place where.
i. Of these there are many instances where inst. expresses direction in a general sense. e.g.,
rājā Māgadho ... Pasenadī-Kosalaṃ abbhuyyāsi yena Kāsī S I.83
“the King of Magadha ... marched against P. Kosala in the direction of Kāsī”;
yena kāmaṃ pakkamati S V.149
“goes whither he likes”;
na yena gāmoti yena disābhāgena assa gantu-kāmatā hoti’ Sum.II. p. 212.45 kāmaṃ gamo D I.72
“unable to go whither he would”.
This is sometimes found reduplicated. e.g.,
yena yen’ eva Bhagavā gamissati tan ninnā va bhavissanti brāhmaṇa-gahapatikā A IV.342
“whichever way the Blessed One goes, the brahmins and householders wend (are bent) that way”;
yena yen’ eva pakkamati ...  D I.71; M I.268
“wherever he goes ...”;
yena yen’ eva ḍeti ... D I.71; M I.180
“where it flies ...”;
yena vā tena vā palāyanti S III.85
“flee this way or that way ...”;
idha pādaṃ karissāmîti aññena eva pādaṃ karomîti M II.69
“(thinking) I shall point my step this way (lit. here) I actually place it in another direction”;
aññena sīsaṃ gacchati aññena kāyo gacchati S II.231
“the head goes one way, the body another way”.
ii. The idiom ‘yena ... tena ...’ found generally with verbs of motion implies the direction, the route by which and sometimes even the place where. Of these the last nuance is the most marked. Buddhaghosa says that it is used in the sense of the loc. e.g.,
yena ‘yenâti, yena disābhāgena so upasankamitabbo. Bhummatthe vā karaṇavacanaṃ...’ Sum. I. p. 48. 46 maṇḍalamālo ten’ upasaṅkami D I.2
“whither the circular pavilion was thither he repaired”;
yena Āḷāra-Kālāmo ten’ upasaṅkami D II.130
“where Āḷāra Kālāma was there he went”.
In the following it implies mere direction:
yena Bhagavā ten’ añjaliṃ paṇāmetvā D II.37; Sn p.100
“pointing his clasped fists (in salutation) in the direction where the Blessed One was”.
Sometimes when the place gone to and the person sought for are both mentioned the adv. yena may be repeated. e.g.,
yannūnāhaṃ yena ... Mallikāya ārāmo yena Poṭṭhapāda paribbājako ten’ upasaṅkameyyanti D I.178
“it would be well if I go where the monastery of Mallikā is, where (lives) Poṭṭhapadā, the wanderer”.
In the following it almost amounts to route along or by which:
yena so kālakato tena rathaṃ pesehi D II.26
“where he has expired send the chariot that way”.
iii. Corresponding to the above we find the idiom ‘yena ... tad ...’ where the verb following tad is one such as normally takes the acc. of the place entered (§40). In tad therefore we have the adv. use of the acc. of place corresponding to the similar application of the inst. of place discussed here. e.g.,
yena ‘yena disābhāgena Icchānangalaṃ avasaritabbaṃ, yasmiṃ vā padese Icchānangalaṃ’ Sum. I .243.47 Icchānaṅkalaṃ ... tad avasari D I.87
“where Icchānaṅkala ... was there he went (lit. entered)”;
cp. M I.166, II.49 ‘tad’.
There is one local adverb of an historical character, viz. chamā “on the ground” (= Vedic kṣamā) M I.387; D III.6; cp. Th 2.112, where the Comy. has ‘chamāyaṃ’ (Th. A. p. 116). 
§82. Instrumental with Adverbial Prepositions.
In Pāli as in Skr. and Vedic (VGS §199.3) genuine prepositions are virtually not used with the inst. We probably find the influence of the adverbal prefix saṃ- “together with” in constructions like mātaram pi puttena samānetā D III.163 as pointed out above (§63.a.ii). But these instrumentals cannot be said to be directly due to saṃ- which only emphasises the fact of association. Even in the Ṛg Veda an independent use of saṃ- with the inst. is hardly perceptible (VGS ibid). But there are a few adverbial prepositions or prepositional particles (nipāta) which were originally adverbs used with the inst. in the Nikāyas. Such are aññatra, alaṃ and vinā (also possibly tiro).
a. The inst. with aññatra expresses the thing set aside or kept off in reckoning. The abl. is the alternate idiom (§130.d). e.g.,
aññatra ekena M I.483
aññatra tena Bhagavatā D II.222
“except that Blessed One”;
cp. D I.168; A I.35. The inst. in these instances seems to be a logical necessity owing to the idea of exclusion or comparison contained in añña- “else, other than”.
b. With alaṃ the inst. expresses a prohibition or an invitation to cease or to stop (SS §76.ii.) like astu and kṛtaṃ in Skr. and similarly means “enough”. In the Nikāyas it nearly always occurs with the emphatic particle dāni “now, verily!”. e.g.,
alaṃ dāni me attha-karaṇena S I.74
“enough of this court-business for me!”;
alaṃ dāni ajja uyyāna-bhūmiyā D II.26
“enough of the pleasaunce for today!”.
c. (Perhaps) vinā “except, bereft of” is also to be included in this list. It occurs in Skr. as an adv. preposition with the inst. or the abl. in the sense of “without” and is there regarded as a sociative preposition like saha, of which vinā is the logical opposite (Macdonell Skr. Gr. §177.b.). It is however not usual in the prose Nikāyas and occurs but rarely in the gāthā literature. e.g.,
ñātisaṅghā vinā hoti
“is bereft of the group of relatives”
Sn 589; cp.
vinā daṇḍena Vin II.132
“without a support”.
In the former however -ā may be the inst. or the abl. sg. ending. 
§83. Idiomatic Uses of the Inst.
The inst. is used in many idiomatic expressions (cp. SS §§74 & 75), most of which logically fall under the categories discussed in the preceding paragraphs.
a. Such is the employment of the inst. with kiṃ meaning “what use or need is there of”. Here the inst. actually expresses the means with an implied verb such as karissati or hoti. In fact in the Vedas it is hardly found without the verb (karoti) showing thereby that originally it denoted the instrument (cp. VGS §199.1.h). kiṃ is usually followed by pana in the Nikāyas. e.g.,
kiṃ pana tena muṇḍakena samaṇakena diṭṭhenâti? M II.46
“what is the good of seeing that shaveling of a recluse?”
lit. “what (sci. shall I do) with that shaveling ... seen?”;
kiṃ pana āyasmato ... serivihārena ... M I.469
“what is the good of an independent life to this elder ... ?”;
kinte iminā pūtikāyena diṭṭhena S III.120
“what is the use of seeing this putrid body”
lit. “what will you do with this putrid body seen?”.
b. Another set phrase similarly used is ‘attho with the inst.’ which means “to be in need of”, where normally hoti is to be understood. e.g.,
Tato bhoto yāvatakena attho tāvatakaṃ āhareyyatanti D II.245
“from it you may take away as much as you are in need of”;
sace bhante piṇḍakena attho ... M I.380
“if Sir, there is a need of food ...”;
cp. D II.176; S I.99; Sn 331. In the last instance we find the inst. with the phrase ‘ko attho’ which is parallel to Skr. ‘kiṃ prayojanaṃ’ (SS §75). Similarly like attho its derivative atthī (cp. Skr. arthin c. inst.) complies with the inst. e.g.,
atthi ‘atthiko pañhena āgato ’mhi’ Pj.II.2. p. 572.48 pañhena āgamaṃ Sn 957,1043
“I have come as one in need of (asking) a question”.
c. Another word employed in a similar manner is karaṇīyaṃ the verbal noun (nt. sg.) from the potential participle of kar-. It means “something to be done”; hence “necessity > need”. e.g.,
roge hi sati bhesajjena karaṇīyaṃ hoti M I.506
“when there is a disease, there is need for medicine”;
appamādena karaṇīyaṃ S IV.125
“need for diligence”;
cetanāya karaṇīyaṃ A IV.312
“need for will”;
cp. P.T.S. Dict. s.v. karaṇīyaṃ. 
d. The set phrase ‘ko pana vādo’, probably elliptical form of ‘ko pana attho vādena’, meaning “what (need to) talk of”, also is construed with the inst. e.g.,
ko pana vādo aññatara-añña tarenâti D III.45
“what need to talk of each in turn”, i.e. “not to talk of each separately”.
We have already had occasion (§80) to refer to the inst. used in the stereotyped adverbial phrase which consists of a prosecutive inst. followed by the acc. of the same word denoting the limit ad quem. There are, however, many other shades of the same idiom where the two cases seem to depend on each other so closely that the syntactical function of the one cannot be considered separately from that of the other. The idiom thus has a compound sense and is nearly always to be regarded as one adverbial phrase. e.g.,
sabbena sabbaṃ Comy. ‘sabbena sabbaṃ sabbathā sabbanti nipāta-dvayaṃ etaṃ, tassa attho: sabbākārena sabbā, sabbena sabhāvena ca sabbā jāti nāma yadi na bhaveyyā ti’. Sum. II. p. 497.49 sabbathā sabbaṃ D II.57,58; M II.367
“completely (altogether, all in all) and everywhere”;
sabbena sabbaṃ sāsanaṃ ājānanti D II.251
“they know the message completely”;
aññena aññaṃ vyākāsi D I.57
“he explained contradictorily”, lit. “one with or in terms of another (quite different)”.
§85. Adnominal Uses of the Inst.
Most of the uses of the inst. discussed in the preceding paragraphs are adverbal. Apart from such there is a distinct class of adnominal instrumentals (cp. KVG §548). The following logical divisions may be observed:
a. With nouns and adjectives like nānākaraṇaṃ, viseso and adhippāyo, meaning “difference, distinction, particularity”, the inst. is one of comparison (§86) and is used parallel to the corresponding abl. (§132.d). e.g.,
Atha kiñcarahi te bhante puthujjanena nānākaraṇaṃ? M I.392
“Then, Sir, where (is) your distinction (difference) from the common man?”;
ko viseso ko adhippāyo kiṃ nānākaraṇaṃ paṇḍitassa bālenâti? S I.24
“what is the peculiarity, the distinction, the difference of the wise man (in comparison with or) from the fool?”;
cp. S III.66; A I.267. 
b. The opposite of difference, viz. equality or similarity, is also expressed by the inst., as with the words sama (cp. VGS §199.B.2.a) and its reduplicated form samasama. Such adjectives also comply with the gen. (§151.b), just as in the older language (SS §61 & §129). e.g.,
Āyasmatā Vidhurena samasamo hoti M I.331
“he is quite equal to the venerable Vidhura’’;
iminā pattena samatittikaṃ M II.7
“equal to a whole bowlful”;
na tena dhammena sam’ atthi kiñci Sn 225
“there is nothing equal to (lit. with) this Doctrine’’.
c. Adjectives denoting fullness and its opposite emptiness also comply with the inst. With puṇṇa (Skr. pūrṇa, KVG §548) “full”
Pāli prefers the older construction with the gen. (§151.b.2.), but suñña “empty, void” is frequently found with the inst. e.g.,
suññaṃ idaṃ attena vā attanīyena vā S IV.54; M I.297; II.263
“this is empty of a Soul or aught pertaining to a Soul”;
suññā ... paricārikehi D II.202
“bereft of ... disciples”;
suññā parappavādā samaṇehi aññe D II.151; M I.64
“other sects are void of recluses”.
Similarly the inst. occurs with the noun ūnaṃ “deficiency”. It is apparent here that it borders on the inst. of relation (§70), for it may imply “deficient in respect of”. e.g.,
sace te ūnaṃ kāmehi ... D II.243
“if there be a deficiency to you (in point) of pleasures ...”.
§86. Inst. of Comparison.
From the preceding discussion it becomes evident that with adjectives denoting equality etc. and their opposites the inst. borders on the so-called Ablativus Comparationis. Even in early Skr. the inst. is found in this connection side by side with the abl. “... there are a good deal of instances proving that Skr. had, especially in the ancient dialect, an inst. of the thing surpassed of the same power as the so-called Abl. Comparationis”. Speyer SS §70.R.l.50 That is why the rendering “in comparison with” is possible in such cases. The same construction is found with adjectives of the comparative degree. e.g.,
na tena seyyo sadiso vijjati D III.158
“there is no one greater than he or equal to him”:
dhanena seyyo M II.73
“better than wealth”;
hīnataro khajjopanakena M II.42
“weaker than a fire-fly”;
Rājā Māgadho ... sukhavihāritaro āyasmatā Gotamena M I.94
“the King of Magadha ... is one who lives happier than the venerable Gotama”;
tena ca vedanā-sokhummena aññaṃ vedanā-sokhummaṃ uttaritaraṃ vā paṇītataraṃ vā na  passāmi A II.18
“I do not see a sense-pleasure nobler or sublimer than this exquisite feeling”;
Thus it is seen that adjectives denoting all the three logical grades, viz. inferiority, equality and superiority, all comply with the inst.
§87. Instrumental of Agent.
According to Skr. grammarians the logical definition of agency (kartṛtva) is that it is the substratum of action. ‘kriyāśrayatvaṃ kartṛtvaṃ’, Philosophy of Skr. Grammar p. 244.51 It is held that the agent is to be distinguished from other case-concepts (kāraka) by virtue of its independent character (svātantrya) and therefore, according to Patañjali, cited Philosophy of Skr. Grammar p. 229.52 the other cases are to be regarded as dependent on it (pāratantrya). For this reason the agent is considered to be the ‘kāraka’ par excellence and the others are called upakārakas, i.e., auxiliary cases. This, however, as a logical difference, does not seem to have struck Pāṇinī forcibly for he summarily deals with both the instrumental and the agent by the same sūtra (§61), whereas Kaccāyana apparently maintains the distinction when he lays down two separate rules (ibid). But, as has been pointed out earlier (§66), according to modem writers, the agent and the instrument are both divisions of the wider category of means (§62).
§88. [Inst. with Verbs]
a. The fundamental use of the inst. of agent is to denote the original (logical) subject with passive verbs (KVG §547), the original object being expressed by the nom. e.g.,
bhotā Gotamena anekapariyāyena dhammo pakāsito D I.110
“the Doctrine was preached by the venerable Gotama in manifold ways”;
taṃ me samaṇena Gotamena okāsakammaṃ kataṃ Sn p.94
“permission was granted to me by the recluse Gotama”.
With the agent of participles and adjectives the present participle santa- is sometimes found implying a continuous temporal sense, just as in the case of the nom. (§26.b); in a sense they border on the absolute use. e.g.,
iti puṭṭhena satā, Ānanda, atthîti assa vacanīyaṃ D I.175
“being thus questioned, Ānanda, you should answer him saying ‘there is’”.
When the inst. of agent is used with verbs  implying association, it has a definite sociative sense. e.g.,
tāya ... parisāya parivuto D II.30
“surrounded by that following”.
Sometimes the agent may be the logical subject of a p.p.p. forming the first member of a compound. e.g.,
Mārena pariyuṭṭhita-cittā D III.57
“with a mind obsessed by Māra”.
b. It is also used as the agent of the infinitive in -tuṃ which exhibits a passive cp. ‘Infinitivus cum Instrumental im Pāli’ Franke, Z.D.M.G.1892.53 sense when employed with sakkā, sukaraṃ etc. (§19.c). e.g.,
sakkā ca pana eso abhavissa ñātuṃ gahapatinā D I.170
“would that be able to be known by a householder?”.
Here the original object is put in the nom. (eso) being the grammatical subject in the passive construction. But there is at least one instance of it being preserved in the acc., unless we are dealing here with an eastern nom. nt. sg. -e of a co-ordinative compound, viz. na dāni sukaraṃ amhehi Franke disagrees with Ed. Müller that this is a dat. as the translation suggests and maintains that it is the inst. of agent. Z.D.M.G. 1892.54
lābha-sakkāra-siloke paricajjituṃ M I.52
“it is not easy for (lit. by) us to discard gain, esteem and praise”.
In the following the form does not show whether it is nom. or acc.:
kallaṃ nu kho tena tad abhinandituṃ D II.69
“is it fitting that he should like it?”;
na idaṃ sukaraṃ ... agāraṃ ajjhāvasatā ... brahmacariyaṃ carituṃ D I.63
“it is not easy for one living at home ... to practise the Higher Life”.
c. Similarly the agent is used with the impersonal construction (both for subject and complement) when the verb is the potential participle or the gerundive (nt. sg.). e.g.,
āraññaken’ āvuso bhikkhunā ... sabrahmacārisu sagāravena bhavitabbaṃ M I.469
“a forest-dwelling monk, friend, should be respectful towards his co-celibates”;
na dāni tena raññā ciraṃ jīvitabbaṃ hoti D III.64
“now that king cannot live longer”.
d. With the causative the subject of the original active verb is denoted by the inst. of agent. This is called the hetu (-kattā) by local grammarians (Kac. 284). The acc. is the more usual idiom here, especially when the verb is intransitive such as those denoting motion (§59). e.g.,
te ... purisehi rakkhāpenti D I.105
“they cause (themselves) to be guarded by men”;
sādhu me bhante Bhagavā tapojigucchāya aggaṃ yeva pāpetu  sāraṃ yeva pāpetûti D III.48
“well, Sir, may the Blessed One make me attain to the summit, to the very essence, of ‘the disgust for asceticism’”;
on the form me see §15.
e. The inst. sg. of the reflexive pronoun attā “self”, viz. attanā, is found in the Nikāyas used with active verbs, mostly in an emphatic sense “by himself, personally”. e.g.,
upāsako attanā saddhāsampanno hoti A IV.221
“the disciple is himself endowed with faith”;
so attanā matto pamatto pare mādetvā pamādetvā S IV.307
“he being himself intoxicated and slovenly having made others (too) intoxicated and slovenly ...”;
attanā jāti-dhammo samāno M I.161
“himself (personally) being subject to birth ...”.
This use of the inst. seems to lie on the borderline between its functions of means and relation. e.g.,
attanā va attānaṃ vyākareyya D II.93
“(by means of) yourself explain yourself”
attanā ca jīvāhi aññe ca posehi D III.66
“live (by means of this money) as far as you are concerned and nourish others”.
Whatever be its origin, attanā has come to be applied in the Nikāyas in an adverbial manner, as in the following where it refers to a plural antecedent:
yadā tumhe Kālāmā attanā va jāneyyātha A I.189
“when you yourselves know, O Kālāmas”.
cp. reflexive svayaṃ in Vedic and Skr. used adverbially in the sense of “spontaneously” VGS. §115.a.
last updated: April 2016