eBook of George Grote, Plato and the Other Companions of Sokrates: Vol. 1 of 4

48 See the remarkable passages in the discourses of Sokrates (Memorab. iii. 1, 6; iv. 2, 15), and in that of Kambyses to Cyrus, which repeats the same opinion — Cyropæd. i. 6, 27 — respecting the amount of deceit, treachery, the thievish and rapacious qualities required for conducting war against an enemy — (τὰ πρὸς τοὺς πολεμίους νόμιμα, i. 6, 34).

Aristotle treats of Dialectic, as he does of Rhetoric, as an art having its theory, and precepts founded upon that theory. I shall have occasion to observe in a future chapter (xxi.), that logical Fallacies are not generated or invented by persons called Sophists, but are inherent liabilities to error in the human intellect; and that the habit of debate affords the only means of bringing them into clear daylight, and guarding against being deceived by them. Aristotle gives precepts both how to thrust, and how to parry with the best effect: if he had taught only how to parry, he would have left out one-half of the art.

One of the most learned and candid of the Aristotelian commentators — M. Barthélemy St. Hilaire — observes as follows (Logique d’Aristote, p. 435, Paris, 1838) respecting De Sophist. Elenchis:—

“Aristote va donc s’occuper de la marche qu’il faut donner aux discussions sophistiques: et ici il serait difficile quelquefois de décider, à la manière dont les choses sont présentées par lui, si ce sont des conseils qu’il donne aux Sophistes, ou à ceux qui veulent éviter leurs ruses. Tout ce qui précède, prouve, au reste, que c’est en ce dernier sens qu’il faut entendre la pensée du philosophe. Ceci est d’ailleurs la seconde portion du traîté.”

It appears to me that Aristotle intended to teach or to suggest both the two things which are here placed in Antithesis — though I do not agree with M. St. Hilaire’s way of putting the alternative — as if there were one class of persons, professional Sophists, who fenced with poisoned weapons, while every one except them refrained from such weapons. Aristotle intends to teach the art of Dialectic as a whole; he neither intends nor wishes that any learners shall make a bad use of his teaching; but if they do use it badly, the fault does not lie with him. See the observations in the beginning of the Rhetorica, i. p. 1355, a. 26, and the observations put by Plato into the mouth of Gorgias (Gorg. p. 456 E).

Even in the Analytica Priora (ii. 19, a. 34) (independent of the Topica) Aristotle says:—χρὴ δ’ ὅπερ φυλάττεσθαι παραγγέλλομεν ἀποκρινομένους, αὐτοὺς ἐπιχειροῦντας πειρᾶσθται λανθάνειν. Investigations of the double or triple senses of words (he says) are useful — καὶ πρὸς τὸ μὴ παραλογισθῆναι, καὶ πρὸς τὸ παραλογίσασθαι, Topica, i. 18, p. 108, a. 26. See also other passages of the Topica where artifices are indicated for the purpose of concealing your own plan of proceeding and inducing your opponent to make answer in the sense which you wish, Topica, i. 2, p. 101, a. 25; vi. 10, p. 148, a. 37; viii. 1, p. 151, b. 23; viii. 1, p. 153, a. 6; viii. 2, p. 154, a. 5; viii. 11, p. 161, a. 24 seq. You must be provided with the means of meeting every sort and variety of objection — πρὸς γὰρ τὸν πάντως ἐνιστάμενον πάντως ἀντιτακτέον ἐστίν. Topic. v. 4, p. 134, a. 4.

I shall again have to touch on the Topica, in this point of view, as founded upon and illustrating the Megaric logical puzzles (ch. viii. of the present volume).

The Sophisms ascribed to Eubulidês, looked at from the point of view of logical theory, deserve that attention which they seem to have received. The logician lays down as a rule that no affirmative proposition can be at the same time true and false. Now the first sophism (called Mentiens) exhibits the case of a proposition which is, or appears to be, at the same time true and false.49 It is for the logician to explain how this proposition can be brought under his rule — or else to admit it as an exception. Again, the second sophism in the list (the Veiled or Hidden Man) is so contrived as to involve the respondent in a contradiction: he is made to say both that he knows his father, and that he does not know his father. Both the one answer and the other follow naturally from the questions and circumstances supposed. The contradiction points to the loose and equivocal way in which the word to know is used in common speech. Such equivocal meaning of words is not only one of the frequent sources of error and fallacy in reasoning, but also one of the least heeded by persons untrained in dialectics; who are apt to presume that the same word bears always the same meaning. To guard against this cause of error, and to determine (or impel others to determine) the accurate meaning or various distinct meanings of each word, is among the duties of the logician: and I will add that the verb to know stands high in the list of words requiring such determination — as the Platonic Theætêtus50 alone would be sufficient to teach us. Farthermore, when we examine what is called the Soritês of Eubulides, we perceive that it brings to view an inherent indeterminateness of various terms: indeterminateness which cannot be avoided, but which must be pointed out in order that it may not mislead. You cannot say how many grains are much — or how many grains make a heap. When this want of precision, pervading many words in the language, was first brought to notice in a suitable special case, it would naturally appear a striking novelty. Lastly, the sophism called Κερατίνης or Cornutus, is one of great plausibility, which would probably impose upon most persons, if the question were asked for the first time without any forewarning. It serves to administer a lesson, nowise unprofitable or superfluous, that before you answer a question, you should fully weigh its import and its collateral bearings.

49 Theophrastus wrote a treatise in three books on the solution of the puzzle called Ὁ ψευδόμενος (see the list of his lost works in Diogenes L. v. 49). We find also other treatises entitled Μεγαρικὸς ά (which Diogenes cites, vi. 22), — Ἀγωνιστικὸν τῆς περὶ τοὺς ἐριστικοὺς λόγους θεωρίας — Σοφισμάτων ά, β — besides several more titles relating to dialectics, and bearing upon the solution of syllogistic problems. Chrysippus also, in the ensuing century, wrote a treatise in three books, Περὶ τῆς τοῦ ψευδομένον λύσεως (Diog. vii. 107). Such facts show the importance of these problems in their bearing upon logical theory, as conceived by the ancient world. Epikurus also wrote against the Μεγαρικοί (Diog. x. 27).

The discussion of sophisms, or logical difficulties (λύσεις ἀπορίων), was a favourite occupation at the banquets of philosophers at Athens, on or about 100 B.C. Ἀντίπατρος δ’ ὁ φιλόσοφος, συμπόσιόν ποτε συνάγων, συνέταξε τοῖς ἐρχομένοις ὡς περὶ σοφισμάτων ἑροῦσιν (Athenæus, v. 186 C). Plutarch, Non posse suaviter vivi secundum Epicurum, p. 1096 C; De Sanitate Præcepta, c. 20, p. 133 B.

50 Various portions of the Theætêtus illustrate this Megaric sophism (pp. 165-188). The situation assumed in the question of Eubulidês — having before your eyes a person veiled — might form a suitable addition to the various contingencies specified in Theætêt. pp. 192-193.

The manner in which the Platonic Sokrates proves (Theæt. 165) that you at the same time see, and do not see, an object before you, is quite as sophistical as the way in which Eubulidês proves that you both know, and do not know, your father.

51 Cicero, in his Academ. Prior, ii. 92-94, has very just remarks on the obscurities and difficulties in the reasoning process, which the Megarics and others brought to view — and were blamed for so doing, as unfair and captious reasoners — as if they had themselves created the difficulties — “(Dialectica) primo progressu festivé tradit elementa loquendi et ambiguorum intelligentiam concludendique rationem; tum paucis additis venit ad soritas, lubricum sané et periculosum locum, quod tu modo dicebas esse vitiosum interrogandi genus. Quid ergo? istius vitii num nostra culpa est? Rerum natura nullam nobis dedit cognitionem finium, ut ullâ in re statuere possimus quatenus. Nec hoc in acervo tritici solum, unde nomen est, sed nullâ omnino in re minutatim interroganti — dives, pauper — clarus, obscurus, sit — multa, pauca, magna, parva, longa, brevia, lata, angusta, quanto aut addito aut dempto certum respondeamus, non habemus. At vitiosi sunt soritæ. Frangite igitur eos, si potestis, ne molesti sint.… Sic me (inquit) sustineo, neque diutius captiosé interroganti respondes. Si habes quod liqueat neque respondes, superbis: si non habes, ne tu quidem percipis.”

The principle of the Sorites (ἡ σωριτικὴ ἀπορία — Sextus adv. Gramm. s. 68), though differently applied, is involved in the argument of Zeno the Eleate, addressed to Protagoras — see Simplikius ad Aristot. Physic. 250, p. 423, b. 42. Sch. Brand. Compare chap. ii. of this volume.

52 Aristot. De Interpret. p. 19, a. 6-20. ὅλως ἔστιν ἐν τοῖς μὴ ἀεὶ ἐνεργοῦσι τὸ δυνατὸν εἶναι καὶ μὴ ὁμοίως· ἐν οἷς ἀμφω ἐνδέχεται, καὶ τὸ εἶναι καὶ τὸ μὴ εἶναι, ὥστε καὶ τὸ γενέσθαι καὶ τὸ μὴ γενέσθαι.

53 Aristot. Metaph. Θ. 3, p. 1046, b. 29. Εἰσὶ δέ τινες, οἴ φασιν, οἷον οἱ Μεγαρικοί, ὅταν ἐνεργῇ, μόνον δύνασθαι, ὅταν δὲ μὴ ἐνεργῇ, μὴ δύνασθαι — οἷον τὸν μὴ οἰκοδομοῦντα οὐ δύνασθαι οἰκοδομεῖν, ἀλλὰ τὸν οἰκοδομοῦντα ὅταν οἰκοδομῇ· ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων.

Deycks (De Megaricorum Doctrinâ, pp. 70-71) considers this opinion of the Megarics to be derived from their general Eleatic theory of the Ens Unum et Immotum. But I see no logical connection between the two.

Now these arguments of Aristotle are by no means valid against the Megarics, whose doctrine, though apparently paradoxical, will appear when explained to be no paradox at all, but perfectly true. When we say that the architect has power to build, we do not mean that he has power to do so under all supposable circumstances, but only under certain conditions: we wish to distinguish him from non-professional men, who under those same conditions have no power to build. The architect must be awake and sober: he must have the will or disposition to build:54 he must be provided with tools and materials, and be secure against destroying enemies. These and other conditions being generally understood, it is unnecessary to enunciate them in common speech. But when we engage in dialectic analysis, the accurate discussion (ἀκριβολογία) indispensable to philosophy requires us to bring under distinct notice, that which the elliptical character of common speech implies without enunciating. Unless these favourable conditions be supposed, the architect is no more able to build than an ordinary non-professional man. Now the Megarics did not deny the distinctive character of the architect, as compared with the non-architect: but they defined more accurately in what it consisted, by restoring the omitted conditions. They went a step farther: they pointed out that whenever the architect finds himself in concert with these accompanying conditions (his own volition being one of the conditions) he goes to work — and the building is produced. As the house is not built, unless he wills to build, and has tools and materials, &c. — so conversely, whenever he has the will to build and has tools and materials, &c., the house is actually built. The effect is not produced, except when the full assemblage of antecedent conditions come together: but as soon as they do come together, the effect is assuredly produced. The accomplishments of the architect, though an essential item, are yet only one item among several, of the conditions necessary to building the house. He has no power to build, except when those other conditions are assumed along with him: in other words, he has no such power except when he actually does build.

54 About this condition implied in the predicate δυνατός, see Plato, Hippias Minor, p. 366 D.

55 Aristot. Metaph. Θ. 3, 1047, a. 3. ὅταν παύσηται (οἰκοδομῶν) οὐχ ἕξει τὴν τέχνην.

2. The Megaric doctrine is the same as that of Protagoras, implying that there exists no perceivable Object, and no Subject capable of perceiving, except at the moment when perception actually takes place.56 On this we may observe, that the Megarics coincide with Protagoras thus far, that they bring into open daylight the relative and conditional, which the received phraseology tends to hide. But neither they nor he affirm what is here put upon them. When we speak of a perceivable Object, we mean that which may and will be perceived, if there be a proper Subject to perceive it: when we affirm a Subject capable of perception, we mean, one which will perceive, under those circumstances which we call the presence of an Object suitably placed. The Subject and Object are correlates: but it is convenient to have a language in which one of them alone is introduced unconditionally, while the conditional sign is applied to the correlate: though the matter affirmed involves a condition common to both.

56 Aristot. Metaph. Θ. 3, 1047, a. 8-13.

3. According to the Megaric doctrine (Aristotle argues) every man when not actually seeing, is blind; every man when not actually speaking, is dumb. — Here the Megarics would have said that this is a misinterpretation of the terms dumb and blind; which denote a person who cannot speak or see, even though he wishes it. One who is now silent, though not dumb, may speak if he wills it: but his own volition is an essential condition.57

57 The question between Aristotle and the Megarics has not passed out of debate with modern philosophers.

Dr. Thomas Brown observes, in his inquiry into Cause and Effect — “From the mere silence of any one, we cannot infer that he is dumb in consequence of organic imperfection. He may be silent only because he has no desire of speaking, not because speech would not have followed his desire: and it is not with the mere existence of any one, but with his desire of speaking, that we suppose utterance to be connected. A man who has no desire of speaking, has in truth, and in strictness of language, no power of speaking, when in that state of mind: since he has not a circumstance which, as immediately prior, is essential to speech. But since he has that power, as soon as the new circumstance of desire arises — and as the presence or absence of the desire cannot be perceived but in its effects — there is no inconvenience in the common language, which ascribes the power, as if it were possessed at all times, and in all circumstances of mind, though unquestionably, nothing more is meant than that the desire existing will be followed by utterance.” (Brown, Essay on the Relation of Cause and Effect, p. 200.)

This is the real sense of what Aristotle calls τὸ δὲ (λέγεται) δυνατόν, οἷον δυνατὸν εἶναι βαδίζειν ὅτι βαδισειεν ἂν, i.e. he will walk if he desires to do so (De Interpret. p. 23, a. 9-15).

4. According to the Megaric doctrine (says Aristotle) when you are now lying down, you have no power to rise: when you are standing up, you have no power to lie down: so that the present condition of affairs must continue for ever unchanged: nothing can come into existence which is not now in being. — Here again, the Megarics would have denied his inference. The man who is now standing up, has power to lie down, if he wills to do so — or he may be thrown down by a superior force: that is, he will lie down, if some new fact of a certain character shall supervene. The Megarics do not deny that he has power, if — so and so: they deny that he has power, without the if — that is, without the farther accompaniments essential to energy.

58 Hobbes, in his Computation or Logic (chaps. ix. and x. Of Cause and Effect. Of Power and Act) expounds this subject with his usual perspicuity.

“A Cause simply, or an Entire Cause, is the aggregate of all the accidents, both of the agents, how many soever they be, and of the patient, put together; which, when they are all supposed to be present, it cannot be understood but that the effect is produced at the same instant: and if any one of them be wanting, it cannot be understood but that the effect is not produced” (ix. 3).

“Correspondent to Cause and Effect are Power and Act: nay, those and these are the same things, though for divers considerations they have divers names. For whensoever any agent has all those accidents which are necessarily requisite for the production of some effect in the patient, then we say that agent has power to produce that effect if it be applied to a patient. In like manner, whensoever any patient has all those accidents which it is requisite it should have for the production of some effect in it, we say it is in the power of that patient to produce that effect if it be applied to a fitting agent. Power, active and passive, are parts only of plenary and entire power: nor, except they be joined, can any effect proceed from them. And therefore these powers are but conditional: namely, the agent has power if it be applied to a patient, and the patient has power if it be applied to an agent. Otherwise neither of them have power, nor can the accidents which are in them severally be properly called powers: nor any action be said to be possible for the power of the agent alone or the patient alone.”

59 Aristotle does in fact grant all that is here said, in the same book and in the page next subsequent to that which contains his arguments against the Megaric doctrine, Metaphys. Θ. 5, 1048, a. 1-24.

In this chapter Aristotle distinguishes powers belonging to things, from powers belonging to persons — powers irrational from powers rational — powers in which the agent acts without any will or choice, from those in which the will or choice of the agent is one item of the aggregate of conditions. He here expressly recognises that the power of the agent, separately considered, is only conditional; that is, conditional on the presence and suitable state of the patient, as well as upon the absence of counteracting circumstances. But he contends that such absence of counteracting circumstances is plainly implied, and need not be expressly mentioned in the definition.

ἐπεὶ δὲ τὸ δυνατὸν τὶ δυνατὸν καὶ ποτὲ καὶ πῶς καὶ ὅσα ἄλλα ἀνάγκη προσεῖναι ἐν τῷ διορισμῷ —

τὸ δυνατὸν κατὰ λόγον ἅπαν ἀνάγκη, ὅταν ὀρέγηται, οὖ τ’ ἔχει τὴν δύναμιν καὶ ὡς ἔχει, τοῦτο ποιεῖν· ἔχει δὲ παρόντος τοῦ παθητικοῦ καὶ ὡδὶ ἔχοντος ποιεῖν· εἰ δὲ μή, ποιεῖν οὐ δυνήσεται. τὸ γὰρ μηθενὸς τῶν ἕξω κωλύοντος προσδιορίζεσθαι, οὐθὲν ἔτι δεῖ· τὴν γὰρ δύναμιν ἔχει ὥς ἔστι δύναμις τοῦ ποιεῖν, ἔστι δ’ οὐ πάντως, ἀλλ’ ἐχόντων πῶς, ἐν οἷς ἀφορισθήσεται καὶ τὰ ἕξω κωλύοντα· ἀφαιρεῖται γὰρ ταῦτα τῶν ἐν τῷ διορισμῷ προσόντων ἔνια. The commentary of Alexander Aphr. upon this chapter is well worth consulting (pp. 546-548 of the edition of his commentary by Bonitz, 1847). Moreover Aristotle affirms in this chapter, that when τὸ ποιητικὸν and τὸ παθητικὸν come together under suitable circumstances, the power will certainly pass into act.

Here then, it seems to me, Aristotle concedes the doctrine which the Megarics affirmed; or, if there be any difference between them, it is rather verbal than real. In fact, Aristotle’s reasoning in the third chapter (wherein he impugns the doctrine of the Megarics), and the definition of δυνατὸν which he gives in that chapter (1047, a. 25), are hardly to be reconciled with his reasoning in the fifth chapter. Bonitz (Notes on the Metaphys. pp. 393-395) complains of the mira levitas of Aristotle in his reasoning against the Megarics, and of his omitting to distinguish between Vermögen and Möglichkeit. I will not use so uncourteous a phrase; but I think his refutation of the Megarics is both unsatisfactory and contradicted by himself. I agree with the following remark of Bonitz:—“Nec mirum, quod Megarici, aliis illi quidem in rebus arguti, in hâc autem satis acuti, existentiam τῷ δυνάμει ὄντι tribuere recusarint,” &c.

60 The dialectic ingenuity of Diodorus is powerfully attested by the verse of Ariston, applied to describe Arkesilaus (Sextus Emp. Pyrrh. Hyp. i. p. 234):

Πρόσθε Πλάτων, ὄπιθεν Πύῤῥων, μέσσος Διόδωρος.

61 Aristot. De Interpret. p. 18, a. pp. 27-38. Alexander ad Aristot. Analyt. Prior. 34, p. 163, b. 34, Schol. Brandis. See also Sir William Hamilton’s Lectures on Logic, Lect. xxiii. p. 464.

62 Arrian ad Epiktet. ii. p. 19. Upton, in his notes on this passage of Arrian (p. 151) has embodied a very valuable and elaborate commentary by Mr. James Harris (the great English Aristotelian scholar of the 18th century), explaining the nature of this controversy, and the argument called ὁ Κυριεύων.

Compare Cicero, De Fato, c. 7-9. Epistol. Fam. ix. 4.

It was thus that the Megaric dialecticians, with that fertility of mind which belonged to the Platonic and Aristotelian century, stirred up many real problems and difficulties connected with logical evidence, and supplied matters for discussion which not only occupied the speculative minds of the next four or five centuries, but have continued in debate down to the present day.

The question about the Possible and Impossible, raised between Aristotle and Diodorus, depends upon the larger question, Whether there are universal laws of Nature or not? whether the sequences are, universally and throughout, composed of assemblages of conditions regularly antecedent, and assemblages of events regularly consequent; though from the number and complication of causes, partly co-operating and partly conflicting with each other, we with our limited intelligence are often unable to predict the course of events in each particular situation. Sokrates, Plato, and Aristotle, all maintained that regular sequence of antecedent and consequent was not universal, but partial only:63 that there were some agencies essentially regular, in which observation of the past afforded ground for predicting the future — other agencies (or the same agencies on different occasions) essentially irregular, in which the observation of the past afforded no such ground. Aristotle admitted a graduation of causes from perfect regularity to perfect irregularity:—1. The Celestial Spheres, with their included bodies or divine persons, which revolved and exercised a great and preponderant influence throughout the Kosmos, with perfect uniformity; having no power of contraries, i.e., having no power of doing anything else but what they actually did (having ἐνεργεία without δύναμις). 2. The four Elements, in which the natural agencies were to a great degree necessary and uniform, but also in a certain degree otherwise — either always or for the most part uniform (τὸ ὡς ἐπὶ τὸ πολύ) — tending by inherent appetency towards uniformity, but not always attaining it. 3. Besides these there were two other varieties of Causes accidental, or perfectly irregular — Chance and Spontaneity: powers of contraries, or with equal chance of contrary manifestations — essentially capricious, undeterminable, unpredictable.64 This Chance of Aristotle — with one of two contraries sure to turn up, though you could never tell beforehand which of the two — was a conception analogous to what logicians sometimes call an Indefinite Proposition, or to what some grammarians have reckoned as a special variety of genders called the doubtful gender. There were thus positive causes of regularity, and positive causes of irregularity, the co-operation or conflict of which gave the total manifestations of the actual universe. The principle of irregularity, or the Indeterminate, is sometimes described under the name of Matter,65 as distinguishable from, yet co-operating with, the three determinate Causes — Formal, Efficient, Final. The Potential — the Indeterminate — the May or May not be — is characterised by Aristotle as one of the inherent principles operative in the Kosmos.

63 Xenophon, Memor. i. 1; Plato, Timæus, p. 48 A. ἡ πλανωμένη αἰτία, &c.

64 Ἡ τύχη — τὸ ὁπότερ’ ἔτυχε — τὸ αὐτόματον are in the conception of Aristotle independent Ἀρχαί, attached to and blending with ἀνάγκη and τὸ ὡς ἐπὶ τὸ πολύ. See Physic. ii. 196, b. 11; Metaphys. E. 1026-1027.

Sometimes τὸ ὁπότερ’ ἔτυχε is spoken of as an Ἀρχή, but not as an αἴτιον, or belonging to ὕλη as the Ἀρχή. 1027, b. 11. δῆλον ἄρα ὅτι μέχρι τινὸς βαδίζει ἀρχῆς, αὔτη δ’ οὔκετι εἰς ἄλλο· ἔσται οὖν ἡ τοῦ ὁπότερ’ ἔτυχεν αὔτη, καὶ αἴτιοι τῆς γενέσεως αὐτῆς οὐθέν.

See, respecting the different notions of Cause held by ancient philosophers, my remarks on the Platonic Phædon infrà, vol. ii. ch. xxv.

65 Aristot. Metaph. E. 1027, a. 13; A. 1071, a. 10.

ὥστε ἡ ὕλη ἔσται αἰτία, ἡ ἐνδεχομέν ἠ παρὰ τὸ ὡς ἐπὶ το πολὺ ἄλλως τοῦ συμβεβηκότος.

Matter is represented as the principle of irregularity, of τὸ ὁπότερ’ ἔτυχε — as the δύναμις τῶν ἐναντίων.

In the explanation given by Alexander of Aphrodisias of the Peripatetic doctrine respecting chance — free-will, the principle of irregularity — τύχη is no longer assigned to the material cause, but is treated as an αἰτία κατὰ συμβεβηκός, distinguished from αἰτία προηγούμενα or καθ’ αὑτά. The exposition given of the doctrine by Alexander is valuable and interesting. See his treatise De Fato, addressed to the Emperor Severus, in the edition of Orelli, Zurich. 1824 (a very useful volume, containing treatises of Ammonius, Plotinus, Bardesanes, &c., on the same subject); also several sections of his Quæstiones Naturales et Morales, ed. Spengel, Munich, 1842, pp. 22-61-65-123, &c. He gives, however, a different explanation of τὸ δυνατὸν and τὸ ἀδύνατον in pp. 62-63, which would not be at variance with the doctrine of Diodorus. We may remark that Alexander puts the antithesis of the two doctrines differently from Aristotle, — in this way. 1. Either all events happen καθ’ εἱμαρμένην. 2. Or all events do not happen καθ’ εἱμαρμένην, but some events are ἐφ’ ἡμῖν. See De Fato, p. 14 seq. This way of putting the question is directed more against the Stoics, who were the great advocates of εἱμαρμένη, than against the Megaric Diodorus. The treatises of Chrysippus and the other Stoics alter both the wording and the putting of the thesis. We know that Chrysippus impugned the doctrine of Diodorus, but I do not see how.

The Stoic antithesis of τα καθ’ εἱμαρμένην — τὰ ἐφ’ ἡμῖν is different from the antithesis conceived by Aristotle and does not touch the question about the universality of regular sequence. Τὰ ἐφ’ ἡμῖν describes those sequences in which human volition forms one among the appreciable conditions determining or modifying the result; τὰ καθ’ εἱμαρμένην includes all the other sequences wherein human volition has no appreciable influence. But the sequence τῶν ἐφ’ ἡμῖν is just as regular as the sequence τῶν καθ’ εἱμαρμένην: both the one and the other are often imperfectly predictable, because our knowledge of facts and power of comparison is so imperfect.

Theophrastus discussed τὸ καθ’ εἱμαρμένην, and explained it to mean the same as τὸ κατὰ φύσιν. φανερώτατα δὲ Θεόφραστος δείκνυσι ταὐτὸν ὃν τὸ καθ’ εἱμαρμένην τῷ κατὰ φύσιν (Alexander Aphrodisias ad Aristot. De Animâ, ii.).