566 STOICS further suppose that the more obvious of Plato's objections had led to the correction of "reason" into "right reason." However that maybe, it is certain from Aristotle (A7c. Eth., vi. 13, ]144b, 17) that virtue was defined as a "habit" in accordance with right reason, and (Diog. Laer., vii. 54) from that the earlier Stoics made right reason the standard of truth. The law which regulates our action is thus the ultimate criterion of what we know, practical knowledge being understood to be of paramount importance. But this criterion was open to the persistent attacks of Epicureans and Academics, who made clear (1) that reason is dependent upon, if not derived from, sense, and (2) that the utterances of reason lack consistency. Chrysippus, therefore, conceded something to his opponents when he substituted for the Logos the new standards of sensation (afcrOriffis) and general conception (n-p&ri i fyis = anticipa- tion, i.e., the generic type formed in the mind unconsciously and spontaneously). At the same time he was more clearly defining and safeguarding his predecessors' position. For reason is con- sistent in the general conceptions wherein all men agree, because in all alike they are of spontaneous growth. Nor was the term Criterion sensation sufficiently definite. The same Chrysippus fixed upon a of truth, certain characteristic of true presentations, which he denoted by the much disputed term "apprehensive" (Ka-raX-^irTiK^ QavTaaia). Provided the sense organ and the mind be healthy, provided an external object be really seen or heard, the presentation, iu virtue of its clearness and distinctness, has the power to extort the assent which it always lies in our power to give or to withhold. Formerly this technical phrase was explained to mean "the perception which irresistibly compels the subject to assent to it as true." But this, though apparently supported by Sextus Empiricus (Adv. Math., vii. 257), is quite erroneous ; for the presentation is called KaraX-nirr6f, as well as Ka-raXtjirriKT] <f>avT atria, so that beyond all doubt it is something which the percipient subject grasps, and not that which grasps or "lays hold of " the percipient. Nor, again, is it wholly satisfactory to explain Karar]irriiCrj as virtually passive, "apprehensible," like its opposite aKard)TTTO^ ', for we find avr iXT)irr IK^J rSiv viroKijj.tv<av used as an alternative phrase (ib. , vii. 248). It would seem that the perception intended to constitute the standard of truth is one which, by producing a mental counterpart of a really existent external thing, enables the percipient, in the very act of sense, to "lay hold of" or apprehend an object in virtue of the presentation or sense impression of it excited in his own mind. The reality of the external object is a necessary condition, to exclude hallucina- tions of the senses ; the exact correspondence between the external object and the internal precept is also necessary, but naturally hard to secure, for how can we compare the two ? The external object is known only in perception. However, the younger Stoics endeavoured to meet the assaults of their persistent critic Carneades by suggesting various modes of testing a single presentation, to see whether it were consistent with others, especially such as occurred in groups, &c. ; indeed, some went so far as to add to the definition "coming from a real object and exactly corresponding with it" the clause "provided it encounter no obstacle." Degrees The same criterion was available for knowledge derived more of know- directly from the intellect. Like all materialists, the Stoics can ledge. only distinguish the sensible from the intelligible as thinking when the external object is present (alaOdvtcrOat) and thinking when it is absent (ivvoeiv). The product of the latter kind includes memory (though this is. upon a strict analysis, something intermediate) and conceptions or general notions, under which were confusedly classed the products of the imaginative faculty. The work of the mind is seen first in "assent"; if to a true presenta- tion the result is "simple apprehension " (Kardh-rityis : this stands in close relation to the KaraX-nirriK^ <f>avra(r'ia > of which it is the necessary complement) ; if to a false or unapprehensive presentation, the result is " opinion " (5rfo), always deprecated as akin to error and ignorance, unworthy of a wise man. These processes are conceivable only as " modes " of mind, changes in the soul's substance, and the same is true of the higher conceptions, the products of generalization. But the Stoics were not slow to exalt the part of reason, which seizes upon the generic qualities, the essential nature of things. Where sense and reason conflict, it is the latter that must decide. One isolated "apprehension," however firm its grasp, does not constitute knowledge or science (eVjo-r^uTj) ; it must be of the firmest, such as reason cannot shake, and, further, it must be worked into a system of such apprehensions, which can only be by the mind's exercising the "habit" (e|<s) of attaining truth by continuous tension. Here the work of reason is assimilated to the force which binds together the parts of an inorganic body and resists their separation. There is nothing more in the order of the universe than extended mobile bodies and forces in tension in these bodies. So, too, in the order of knowledge there is nothing but sense and the force of reason maintaining its tension and connecting sensations and ideas in their proper sequence. Zeno compared sensation to the out- stretched hand, flat and open ; bending the fingers was assent ; the clenched fist was "simple apprehension," the mental grasp of an object ; knowledge was the clenched fist tightly held in the other hand. The illustration is valuable for the light it throws on the essential unity of diverse intellectual operations, as well as for enforcing once more the Stoic doctrine that different grades of knowledge are different grades of tension. Good and evil, virtues and vices, remarks Plutarch, are all capable of being " perceived"; sense, this common basis of all mental activity, is a sort of touch by which the ethereal Pneuma which is the soul's substance recognizes and measures tension. With this exposition we have already invaded the province of Logic, logic. To this the Stoics assigned a miscellany of studies rhetoric, dialectic, including grammar, in addition to formal logic, to all of which their industry made contributions. Some of their innovations in grammatical terminology have lasted until now : we still speak of oblique cases, genitive, dative, accusative, of verbs active (op6a), passive (forria), neuter (oiiSe'repa), by the names they gave. Their corrections and fancied improvements of the Aristotelian logic are mostly useless and pedantic. Judgment (dluojua) they defined as a complete idea capable of expression in language (Ae/ci-by avroreXes), and to distinguish it from other enunciations, as a wish or a command, they added "which is either true or false." From simple judgments they proceeded to compound judgments, and declared the hypothetical syllogism to be the normal type of reason, of wJiich the categorical syllogism is an abbreviation. Perhaps it is worth while to quote their treatment of the categories. Aristotle made ten, all co-ordinate, to serve as "heads of predication " under which to collect distinct scraps of information respecting a subject, probably a man. For this the Stoics substituted four summa genera, all subordinate, so that each in turn is more precisely determined by the next. They are Something, or Being, determined as (1) substance or subject matter, (2) essential quality, i.e., substance qualified, (3) mode or chance attribute, i.e., qualified substance in a certain condition (TTUS eX ov )> and, lastly, (4) relation or relative mode (in full inroKeifj.evoi' iroi'bv irp6s rt ircas ex oj/ )- T ne zea ^ w "ith which the school prosecuted logical inquiries had one practical result, they could use to perfection the unrivalled weapon of analysis. Its chief employ- ment was to lay things bare and sever them from their surround- ings, in order that they might be contemplated in their simplicity, with rigid exactness, as objects of thought, apart from the illusion and exaggeration that attends them when presented to sense and imagination. The very perfection and precision of this method constantly tempted the later Stoics to abuse it for the systematic depreciation of the objects analysed. The practical philosophy of the Stoics stands in the Ethics, closest connexion with their physics and psychology. Holding that man is a being who acts as well as thinks, and that this is the all-important side of his life, they find the link between the two in the mind's assent ; for, when impelled towards certain objects by a prompting or " impulse " (opfjirj = movement of the soul seeking to possess itself of certain external things), whether of nature or reason, a man must needs judge the objects to be desirable ; the subsequent movement, as it were, translates this judgment into action. Against the sceptical position it was necessary to maintain (1) that motion, and there- fore moral action, cannot follow upon the mere present- ment of an idea, unless the idea so suggested receive assent, and (2) that assent alone does not suffice without the motive faculty which is found in all animals. 1 Of our various impulses, some in the mature man are (a) rational ; some, as in the child, are (/8) non-rational, because anterior to reason ; while (y) the impulse of the man may be contrary to reason, under the influence of the affections or passions, (a) Now reason, as a spring of action, has for its aim harmony or self-consistency, a life proceeding upon a single plan (TO 6/AoAoyou/x.mos tjjv, TOVTO 8' ecrri KdO' eva Xojov KCLL O-U/A<COI/COS tfiv) : in this there is a certain symmetry or beauty, the attraction which excites rational impulse towards it. Clearly this definition of the end of action comes from the Cynics, who pithily expressed it by saying that in order to live man needs either reason or a halter (8elv oyov rj Ppoyov). But during Zeno's early studies another conception had been current, that of agree- ment with nature. Apparently it had been started by the Old Academy, where probably the technical phrase " first Rational impulse. 1 irdcras Se ras 6p/j.as crvyKaraOfrrtis slvai, ras 8e irpaKTtKas Hal i-b KifrjTiK^iv irfpiexftv, Stobseus, Ed. Eth., ii. 164.
