then for him they the πνεῦμα as well as the blood. For Plato air with The secrets of the main life and sensory processes are to be πνεῦμα. Tóρo, whatever they were, conveyed in Aristotle's opinion must have more than the blood1. We are told expressly that those contained of hearing and smelling are full of σúμþvтov tveûμa, and this in such a connexion as to lead us to think that the veμa is the sensory agency in them. On the other hand the 'veins' Aristotle often refers to the blood in a manner which leads conveyed one to suppose that he regarded it-at all events in its the blood. grosser form-as a mere impediment to the transmission of sensory impressions. It is this that, when it gathers origin and around the heart in sleep, fetters To Kúρtov-the faculty of tenance of judgment. The residual movements in the outer senseorgans are liberated successively 3 in sleep as the blood in these organs is diminished. The senses that are most found in the exact—àкpißéσTaTaι—are found in the parts where the bloodvessels are finest and thinnest, and where the blood is coolest and purest, i.e. near the brain 1. Thus on the whole it would appear-though Aristotle has not worked his conception out clearly-as if he conceived the sensory effects to be conveyed with the blood, in the same vessels, but not to be affections of the blood itself or primarily connected with it, but rather with the ouμpurоv Tveûμa. This view seems decisively confirmed by one clause of a passage already quoted, κατιόντος τοῦ αἵματος ἐπὶ τὴν ἀρχὴν συγκατέρχονται αἱ ἐνοῦσαι κινήσεις 5. He had before illustrated the nature of the κινήσεις as like eddies in a stream-ὥσπερ τὰς μικράς δίνας τὰς ἐν τοῖς ποταμοῖς γινομένας. Thus it might seem fairly as if the kinσes of sensation were small 'purls' in the blood, produced by the veûμa, as an interfering force; dependent on the blood, and furthered or restrained by it according to its temperature and quantity, but preserving a form and direction derived from and sustained by 1 In the History of Animals, 496a 30, we read éñávw d' eiσìv oi àñò tñs καρδίας πόροι· οὐδεὶς δ ̓ ἐστὶ κοινὸς πόρος, ἀλλὰ διὰ τὴν σύναψιν δέχονται τὸ πνεῦμα καὶ τῇ καρδίᾳ διαπέμπουσιν. Plato, too, held that air passes through the blood-vessels. See Tim. 82 E. 2 461b 27 and several other passages. * So I take Avóμeval, not with Neuhäuser (op. cit., p. 131) as 'losing their determinateness.' 4 ♦ 461b 18. 5 461a 8 seqq. the veûμа. A similar doubt affects us as to what Plato conceived to be the exact agency in the conveyance of sensory impressions. Are the pλéßia, by which in the Timaeus he represents these impressions as distributed through the body, agents of such distribution in virtue of the blood contained in them, or in virtue of the air which (according to Plato) they also contain? The former is the assumption made by Zeller'. Our difficulty with respect to Aristotle largely arises from his use of the ambiguous word nópoɩ to designate the vessels, or connexions generally, of the sensory organs. In some cases this possibly means nerves". In others it certainly means blood-vessels. We are unable to say always which it is in any given case 3. At all events the σύμφυτον πνεῦμα was conceived by him as having its apy in the heart, where also that of the blood lies. From this ἀρχή the σύμφυτον πνεῦμα diffuses vital heat throughout the body. The σúμдνтоν пνeûμa is different, of course, from the veûμa of respiration, but takes the place of the latter in creatures which do not respire. It was certainly, on the other hand, the opinion of Aristotle that the blood-vessels are channels of sensory processes. On the whole it seems probable that, while the blood in these vessels was (as Aristotle himself might say) ovvaíтɩov, or a joint agent in the conveyance of such processes from the organs of outer to the organs of inner sense, the σúμovтov лveûμa held rather the office of atriov or principal agent. This becomes more probable the more we reflect on the importance of such TVεûμа in Aristotle's biology. The 'energetic' factor in the generation of living creatures consists of νeîμа. We 1 Plato (E. Tr.), p. 429 n., cf. Plato, Tim. 65 C, 67 B, 70 A seqq., 77 E. 2 The theory of 'animal spirits,' coursing along the nerves, which persisted so long even in modern psychology, dates from the connexion of Tóρo in this sense (which after the discovery of the function of nerves was natural enough) with Aristotle's σúμþvтov пveûμa. Cf. p. 86, n. I supra. 3 We must avoid the common error of supposing that Aristotle regarded the arteries as conveying only air. This arises from ignorance of the meaning of aprŋpía in Aristotle, for whom it was the тpaxeîa (áprηpía) or windpipe. Besides he did not even know of the difference between veins and arteries in the modern use of these terms. are told by Aristotle that what makes seeds fruitful is Tò Oepμóv-the 'caloric' which they contain. This caloric, however, is not ordinary fire, but a πveûμa, or rather a natural substance (púois) inherent in this veûμa; a substance like or analogous to the element of which the celestial bodies consist. The blood is thus a comparatively late formation in the animal economy. The veûμa is at the very origin of the life process; and for Aristotle the origin of life must contain potentially (in the case of animals) that of sense. Therefore if we could discover all the properties and functions of the σúμovтоv пveûpa, we should (from Aristotle's point of view) have penetrated to the inmost secrets of sense-perception, not merely as regards the origin of the μεσότης oι λόγος which essentially characterizes a sensory organ, but also as regards the means provided by nature for the distribution of sensory messages within the organism, and the conveyance of sensory impressions, from the eye and ear and other external senses, to the organ governing them all1. The σúμouтov Treûua had, for him, a primordial and subtle efficacy operative throughout the origin and development of animal existence. It was the profoundest cause and the most intimate sustaining agency from beginning to end of life and sensory power. 1 Cf. 736 33-737* Ι πάντων μὲν γὰρ ἐν τῷ σπέρματι ἐνυπάρχει, ὅπερ ποιεῖ γόνιμα εἶναι τὰ σπέρματα, τὸ καλούμενον θερμόν. τοῦτο δ' οὐ πῦρ οὐδὲ τοιαύτη δύναμίς ἐστιν, ἀλλὰ τὸ ἐμπεριλαμβανόμενον ἐν τῷ σπέρματι καὶ ἐν τῷ ἀφρώδει πνεῦμα καὶ ἐν τῷ πνεύματι φύσις, ἀνάλογον οὖσα τῷ τῶν ἄστρων στοιχείῳ. ! INDICES I. ENGLISH Absent, the, how known, 311. Air, all things reducible to, 141; not ALCMAEON, on vision, 11-13; hearing, Alexander of Aphrodisias, 16, 30, Analogy of odours to tastes, sensible ANAXAGORAS, on vision, 37-40; sensus Animals, large compared with small as regards sensory power, 103; as which possess time-sense, have Antipheron of Oreus, 294, 312. constitution of visual organ, 81-6; Arteries, convey air, 5; in modern Artistic genius, 305. Association (so-called) of ideas, i. e. Atomistic theory of colours, 72. Auburn, 52. Bacon, R., 26, 59. Bäumker, C., 11, 77, 113, 148, 191, Birds find prey by smell, 148. Black, seen by water in eye, 19; Blass, F., 19. Blending of colours, 69, 73. Blow-hole, odours perceived through, Blue, deep, 33, 52, 61. Body, as whole, takes part in visual Brain, all senses connected with, 132, Brightness, as distinct from colour, Bronze colour, 33. Burnet, Prof., 16, 133. Bywater, Prof., 170. Clidemus, 257-8. |