Greek theories of elementary cognition from Alcmaeon to Aristotle / by John I. Beare.

  • Beare, John Isaac, -1918.
Date:
1906
Catalogue details

Licence: Public Domain Mark

Credit: Greek theories of elementary cognition from Alcmaeon to Aristotle / by John I. Beare. Source: Wellcome Collection.

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    sense with the general organ for the media¬ tion of the sensory- processes between them. The agency of the blood in this connexion. Is it the actual vehicle of sense im¬ pressions ? Or is it only a con¬ comitant, which may impede as well as further their progress ? At all events to favour sensory processes the blood must be cool and pure. the special or peripheral to the central or general sense- organ. The principal passages containing information respecting this function of the blood-vessels are found in the third chapter of the tract de Insomn., which deals with the way in which, from residuary movements continuing in the sensory organs after alaOrjcns, * appearances * arise in consciousness, not only in waking moments but in time of sleep. The residuary movements are conveyed inwards from the special organ—their origin and home, when not actualized or ‘in consciousness —to the central organ. ‘ We must suppose,’ he says, ‘ that, like the little eddies which are for ever being formed in rivers, the sensory movements are processes continuous but distinct from one another . . . When one is asleep, according as the blood subsides1 and retires inwards towards its fountain, these residual move¬ ments whether potential or actual accompany it inwards 2, They are so related that, if anything has caused some par¬ ticular movement in the blood, some given psychic movement comes to the surface, emerging from it3, while, if this fails, another takes its place. They are to one another like certain toys consisting of artificial frogs4 submerged in water, which rise in a fixed succession to the surface, according as the various quantities of salt, which keep them severally submerged, become successively dissolved, and so release them 5 from their submersion.’ The move¬ ment of heat in the blood, however, interrupts the course of the sensory movement6. Hence the more exact kinds 1 461a 8, 464b 8 seqq. 2 The potential are those which have been already in consciousness, but have sunk into latency, the actual are, we must suppose, the waking perceptions which accompany us into the land of sleep : those which have not yet ceased to affect consciousness, or keep occurring up to the moment when sleep supervenes. 3 46113 14 e£ avrovj SC. rou alparos. 4 ebcrrrep oi TrenXacrpevoi ^arpa^oi oi aviovres iv rw vdan rr/Kopevov tov a\6s. Some well-known invention—possibly for the amusement of chil¬ dren—of the time is referred to. So Kant refers to Vaucanson’s ‘ duck.5 5 For the function of the blood in disseminating Kivrjaeis, cf. Plato, Tim. 70 a seqq. and § 18, p. 271 supra. 6 656b 5 eKKonrei yap f] trjseu rto aipan deppoTijTOs Kivijo-is rr)p alo-QrjTiicrjv evepyztav.