all the aloenripia that are either (a) possible in point of constitution from the four elements, or (b) requisite for the perception of existing σuara and their άon. To restate the points of Aristotle's argument more briefly. Our faculty of perception in general (rò alo◊ŋtɩkóv) is equipped with the needful means of perceiving all alo0nrá. It has, by ȧon, the means of perceiving all which do not need an external medium, i. e. all whose diapopaí belong to body qua body, and characterize the two σroxeîa, fire and earth. It has, by organs constituted of air and water, the means required for perceiving all the air@nrá which do need an external medium: i. e. those whose diapopać do not depend on fire and earth. No aio@nróv, therefore, remains inaccessible to perception with our present senses1. 1 In the parenthetic words 424b 30 exei d' outws to 425a 2 di' àμþoîv Aristotle shows how it is conceivable that there should be a reduction in the number of αἰσθητήρια, or a duplication of αἰσθήσεις or (what comes to the same thing) of aloeŋrá; but leaves it plain that in no such case could we imagine the list of our airbhoes to be usefully increased. For (a) we can conceive one aloŋrnpiov so constituted as to perceive two heterogeneous alonтá; as, for example, if air is medium for both vópos and xpóa, and if it be necessary that an alo@nrýpiov essentially of air should perceive both of these. Again (b) we can also conceive two aionτýpia so constituted that either might perceive the same aio@nróv as the other; as, for example, if air and water are each a competent medium of xpóa, a person with two organs essentially consisting the one of water, the other of air, should with either perceive xpóa. But neither (a) nor (b) would point the way towards an increase in the list of useful alo@noes. The former would give us the same two aio@noeis and aloðŋrá as we have, only by one organ instead of two. The latter only brings us to the conception of two different organs employed in giving us one and the same aïodnois οι αἰσθητόν. The sensus the syn thetic sense. functions mination and comparison, conscious nation and remi PART III. SENSUS COMMUNIS § 1. WE now come to one of the most interesting porcommunis, tions of the ancient Greek psychology-the theory of the faculty of synthesis at its earliest stage. The name which faculty of heads the chapter is a translation of the term κown aloOnois1, Its which was used first by Aristotle for this faculty. It is (a) discri- necessary here, as before, to consider how much of what he had to say regarding it was to be found in the speculations of his predecessors. As, however, these did not, (b) perception of ra at least until Plato's time, undertake the discussion of the Ková, (c) faculty of synthesis as such, we must content ourselves with ness of per- stating the functions ascribed by Aristotle to the Kown ception, (a) imagi- aloonois, and seeing how these functions were dealt with by preceding psychologists. To this department of x, (reproductive), (e) then, variously named by him ἡ κοινὴ αἴσθησις, τὸ κρῖνον, memory тò пρŵτоν aiσonтikóv, he assigned (a) the power of disniscence, criminating and comparing the data of the special senses, sleep all of which are in communication with it; (b) the pering. The ception of the 'common sensibles,' rà κová, of which the tive part of principal are κίνησις σχῆμα ἀριθμὸς μέγεθος and χρόνος ; sensation (c) the consciousness of our sensory experiences, i. e. the to by the power by which we not only perceive, but perceive that we pre-Plado so; (d) the faculty of imagination, i. e. reproductive tonics, imagination-rò pavraσTIKÓν; (e) the faculty of memory and reminiscence, výμn kaì áváμvnois; and (ƒ) the affections of sleeping and dreaming. To ascertain, therefore, how much of Aristotle's theory respecting this had been anticipated, we must survey the works of his predecessors. As they do not (until we reach Plato) distinctly formulate the idea of a synthetic faculty, we can only examine what they may have done to explain the various phenomena of mind abovementioned as attributed by Aristotle to the agency of the and dream presenta attended the repre sentative not so much. 1 Though Aristotle uses this actual term but seldom (cf. 425a 27, 450a 10, 686a 31), often employing equivalents like πpôтov alσðŋtɩkóV, &c., yet as a convenient name for an important conception it was generally adopted by his followers, and in its Latin form continued to play a great part throughout the psychology of the Middle Ages. κοινὴ αἴσθησις. We shall find before Plato very little in the remains of the old psychologists on this important subject of synthesis. We have already recounted what they had to say of the special senses and sensation generally; and from this it is clear that they did not neglect the presentative department of psychology. As regards the representative, however, they do not seem to have taken nearly the same pains. They referred the above-named functions to ψυχή, or vous, in a vague and general fashion ; feeling perhaps that these functions were too complicated and obscure for treatment in detail with any prospect of success. Before Plato, moreover, we find no record of any serious psychological treatment of memory or imagination. must be § 2. Owing to the parallelism in Aristotle's theory Sensus between psychical wholes and parts, the consideration of communis the sensus communis will divide itself into sections corre- studied as to its sponding to the divisions adopted with reference to each function of the special senses. This, their common centre, has its and organ, its objects, function and organ, its objects, and its medium, and will and its have to be investigated with reference to each of these. medium, just like As we have premised that none of the pre-Platonic psycho- each parlogists distinctly conceived such a subject as this, our sense. treatment must (following such records as we possess) be of a piecemeal character, according as we find reason to suppose that each, or any, of the writers with whom we have to do, took or would naturally take a particular view of any of the functions of the common sense, or ascribed any of them to some particular organ. Alcmaeon. ticular No treatment by § 3. Of the function of a sensus communis, or of synthetic Alcmaeon. function in general, Alcmaeon had no distinct idea, as far as his remains and the testimony respecting him can him of synthetic be trusted for information. We know, indeed, that he is function, said to have distinguished sensibility or sense-perception either (alotáveσbai) from intelligence (rò Evviévai), and to have or sensuconfined the possession of the latter to human beings. But us. haps an he has left no evidence to show where he regarded ato@nois implication. as ending or Cúveris as beginning, or how he would the word intellectual of it in Per ξυνιέναι intelli distinguish these. Except, then, for the form of this word gence; so úveσis, which implies synthesis in its notion, and seems seeming ex to ascribe it (as Plato did) to understanding, we have no to ascribe hint that Alcmaeon paid attention to it. Its importance synthetic remained submerged under a familiar name, and it eluded vi termini, function (as Plato did) to under Brain discussion. As little do we know of any classification of objects of sense-perception by him in which he would standing. distinguish the data of special from those of 'common ' would for sense. If, however, he had had a conception of this sense, he would probably have assigned the brain as its organ. There can be no doubt that he silently included the functions of the common sense under those of §úveσis, and we have abundant evidence that for him the brain was the him (as also for Plato) have been organ of synthetic faculty. menon which the blood. Sleeping organ of intelligence, and that, moreover, all the several alo@noes are connected with it and cannot discharge their functions if their connexion with it is disturbed 1. Sleeping depends on (which according to Aristotle is an affection of the sensus communis) results, according to Alcmaeon (as well as to his successors, including Aristotle), from the retirement of the blood into the larger blood vessels, while 'waking (i. e. full consciousness) returns after its rediffusion 2. This might seem to imply that for Alcmaeon the blood would have been the chief organ of consciousness. But we know that sensation was for him impossible without the co-operation of the éyképaλos with each sense; and therefore, most probably, as Siebeck3 remarks, it is to this organ that he would have assigned the consciousness of sensation, which Aristotle ascribes to the organ of the sensus communis, viz. the heart. 1 Theophr. de Sens. § 26 ἁπάσας δὲ τὰς αἰσθήσεις συνηρτῆσθαί πως πρὸς τὸν ἐγκέφαλον, διὸ καὶ πηροῦσθαι κινουμένου καὶ μεταλλάττοντος τὴν χώραν ἐπιλαμβάνειν γὰρ τοὺς πόρους, δι ̓ ὧν αἱ αἰσθήσεις. Cf. also Plut. Εpit. iv. 17, 1, Diels, Dox., p. 407, where, however, the term тò ηyeμovikóv shows how far we are from the text of Alcmaeon. This Stoic term is probably derived from the Aristotelean rò youμevov, 1113a 6. Plato, no doubt, refers to Alcmaeon in Phaedo 96 B: ó ràs aloðnσeis nарéɣшV TOÙ ἀκούειν καὶ ὁρᾶν καὶ ὀσφραίνεσθαι. It is to Alcmaeon and Plato that Aristotle probably alludes, 469 22: διὸ καὶ δοκεῖ τισὶν αἰσθάνεσθαι τὰ ζῷα διὰ τὸν ἐγκέφαλον. 2 eis tàs aiμóppovs pλéßas, Plut. Epit. v. 24, Diels, Dox., p. 435. Empedocles. docleslack a synthetic no any sort. and ment in us perceives 'Each ele outside us.' Whatever must have instrument § 4. We miss, in the information which we have respecting EmpeEmpedocles, anything which would show that he had ck of a a conception of the synthetic faculty as something which conception, on his part, it was the duty of a philosopher-or even a psychologist-of the to discuss; for to reason from his metaphysical conceptions necessity of of piλía and veîkos to psychological analogues of synthesis faculty of and analysis would be merely fanciful. He gives psychological classification of the objects of sense, whatever is to be known respecting his attitude towards its like the sensus communis must be altogether, as in the case of Alcmaeon, due to inferences more or less doubtful. We synthesis know that for him the blood-more especially that in the was possibly conregion of the heart-was the seat or organ of intelligence. templated by him As he did not really distinguish sense from reason or intelligence1, this must show that the blood would have had its been for him the organ of a central faculty of sense had in the mixhe distinctly formed a conception of this. But we have ture of the no information as to how he regarded the añоррoaí, which contained entered the pores of each sense, as co-ordinated and mar- blood, shalled into the service of a systematic experience. He especially does not exhibit a feeling of the need of any such process; the heart but the blood (in which the elements are most perfectly mixed) would, no doubt, have, for him, supplied the organic means towards it. In his theory of 'temperaments 2,' by temperawhich men possess talents according to the perfection of adverse to the xpâσis of the elements in various parts of the body, he tion of seems to betray a singular absence of any perception of a central the need of systematization of sensory data under some faculty. controlling central power. Aristotle notices this fault in the Aristotle psychology of Empedocles, and complains that he does not the neglect provide any central force to combine or keep together and function as of synthetic co-ordinate either the various energies or the elemental parts a defect 1 E. Rohde, Psyche, § 464, note 2, holds that Empedocles did draw this distinction, though admitting that for him rò voeîv was only σωματικόν τι. Cf. Arist. 427a 22. 2 Cf. Theophr. de Sens. § 11. The man who has the elements most perfectly mixed in the tongue is the orator; he who has the mixture perfect in the hand is the artist, and so on. elements in the that round or heart. His ments,' the concep synthetic criticizes |