Theophrastus, De sensu [10th SEAAP Conference, Athens, 23-24 October 2015]
Pavel Gregoric
25-26 Alcmaeon
25-26report of Alcmaeon’s views
25i. makes a distinction between humans and other animals: only humans
haveunderstanding in addition to perception
ii. views about particular senses
a. hearing
b. smell
c. taste
26 d. vision
iii. all senses (or sense-organs) somehow converge towards the brain
iv. objection: Alcmaeon does not state how touch operates
28-37 Anaxagoras
28-30report of Anaxagoras’ views
28i. perception comes about by contraries
ii. views on particular senses
a. vision
- comes about by reflection of the korê
- requires contrast between objects reflected and the korê
- light is a contributing cause of reflection
b. touch and taste
- also require qualitative contrast between object and sense-organ
- tactile and gustatory perception occurs kat’ elleipsin,since the sense-
organ of touch and taste are themselves qualified by tangible
properties and flavours
c. smell and hearing
- smell occurs together with inhaling
- hearing occurs by way of sound reaching the brain, on account of the
surrounding bone being curved
29iii. all perception is accompanied by pain
a. follows from the general assumption that ‘any unlikein contact with an
unlike causes toil’
b. evidence: we cannot endure excessively strong objects of
percept for a long time
iv. sharpness of perceptioncorrelates with the size of animals andof the
sense-organs
a. example of vision
30b. example of hearing
c. example of smell
31-37 criticism of Anaxagoras’ views
31i. it makes sense to argue that perception occurs by contraries, given that
alteration occurs by contraries and perception is alteration (though more needs to be said)
ii. objections to the view that perception is always accompanied by pain
a.in contradiction with empirical facts: some perceptions are
accompanied by pleasure, and most of them are not accompanied by pain
b. in contradiction with theory: perception is in accordance with nature,
and nothing that is by nature is accompanied by pain
32c. if thinking is not accompanied by pain, neither is perception – given that they both aim at cognition of things
d. excessively strong objects of perception and the inability to stand them
very long does not constitute evidence for the view that perception is
always accompanied by pain
33e. this view amounts to an illicit generalization about a natural process
from unnatural (non-standard) cases
34iii. objections to the view that perceptiveness correlates with the size of animals
and of the sense-organs
a. it seems that smaller animals are actually more perceptive, given that:
i. sharpness of perception consists in discriminating small things
ii. it is reasonable to suppose that an animal which can discriminate small things can also discriminate large ones
iii. it seems that with regard to some senses small animals are actually more perceptive than large animals
35b. perceptiveness seems to have less to do with the size of the body and of the sense-organs, and more to do with the bodily disposition and
mixture
c. correlating the size of the objects and the sense organs is similar to
Empedocles explaining perception in terms of effluences fitting the
passages of the sense-organs
d. it is inconsistent to claim that thin air is more odorous, yet that animals
which inhale thick air have a sharper sense of smell than animals that
inhale only thin air
36 iv. objections to the reflection theory of vision
a. the sizes of things seen and of the reflections do not correspond
b. there can be no reflection of many contrary things at the same time
c. some things are visible yet they do not produce reflection, e.g. motion,
distance, size
d. some animals have eyes such that no reflection can occur on them, e.g.
animals with hard eyes and aquatics
e. if reflection is the cause of visual perception, many inanimate things
should see, e.g. surface of the water, polished bronze and many other reflective things
37f. more particular objections against claims developed in support of the
reflection theory of vision
i. if colours are reflected in one another, as A. claims, most of all
intense colours in weaker ones, it follows that colours should
see, especially black and other weak colours
ii. we do not see light itself by any reflection
iii. ‘black things are not deprived of light any more than the white
things’
iv. we see reflections in other things too as they become more
bright and pure
v. given what he says about light, Anaxagoras seems to support
the popular ancient theory that sight/eyes belong to fire because
colours are especially connected with fire
- he does introduce innovations in his account of the particular senses, and especially into his account of vision when he introduces the correlation of size and perceptiveness, though he fails to elucidate in detail the more corporeal senses.
PASSAGES
(1) Theophrastus, De sensu 26, 507.1-3 DG
ὁρᾶν δὲ τῷστίλβοντι καὶ τῷ διαφανεῖ, ὅταν ἀντιφαίνῃ, καὶ ὅσῳ ἂν καθαρώτερον ᾖ,μᾶλλον.
(2) Theophrastus, De sensu 27, 507.12-14 DG
ἐμφαίνεσθαι δὲ μεθ' ἡμέραν, ὅτι τὸ φῶς συναίτιον
τῆς ἐμφάσεως· τὴν δὲ χρόαν τὴν κρατοῦσαν μᾶλλον εἰς τὴν ἑτέραν ἐμφαί-
νεσθαι.
(3) Theophrastus, De sensu 32, 508.14-17 DG
ἔτι δ' ἐπεὶ καὶ ἡδονὴ καὶ λύπη γίνεται διὰ τῆς αἰσθήσεως, ἅπαν δὲ φύσει
πρὸς τὸ βέλτιόν ἐστι, καθάπερ ἡ ἐπιστήμη, μᾶλλον ἂν εἴη μεθ' ἡδονῆς ἢ
μετὰ λύπης. ἁπλῶς δ' εἴπερ μηδὲ τὸ διανοεῖσθαι μετὰ λύπης, οὐδὲ τὸ
αἰσθάνεσθαι· τὸν αὐτὸν γὰρ ἔχει λόγον ἑκάτερον πρὸς τὴν αὐτὴν χρείαν.
(4) Theophrastus, Metaphysics 8b10-14
ἡ γὰρ αἴσθησις καὶ τὰς διαφορὰς θεωρεῖ καὶ τὰς αἰτίας ζητεῖ· τάχα δ᾿ ἀληθέστερον εἰπεῖν ὡς ὑποβάλλει τῇ διανοίᾳ τὰ μὲν ἁπλῶς ζητοῦσα, τὰ δ᾿ ἀπορίαν ἐνεργαζομένη…
(5) Theophrastus, De sensu 35, 509.6-8 DG
εἰ δ' αὖ φαίνεταικαὶ πολλὰ λανθάνειν τὰ μικρά [τῶν μειζόνων οἷον οἱ ψόφοι, χρώματα secl. Diels, Stratton],βελτίων ἡ τῶν μειζόνων·
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