Early Greek Philosophy by John Burnet, with Burnet's notes
117. Physiology 119. Theology and Religion

From Chapter V., Empedokles of Akragas

118. Perception
For the theory of perception held by Empedokles we have the original words of Theophrastos:

Empedokles speaks in the same way of all the senses, and says that perception is due to the "effluences" fitting into the passages of each sense. And that is why one cannot judge the objects of another; for the passages of some of them are too wide and those of others too narrow for the sensible object, so that the latter either hold their course right through without touching or cannot enter at all. R. P. 177 b.

He tries, too, to explain the nature of sight. He says that the interior of the eye consists of fire, while round about it is earth and air,132 through which its rarity enables the fire to pass like the light in lanterns (fr. 84.). The passages of the fire and water are arranged alternately; through those of the fire we perceive light objects, through those of the water, dark; each class of objects fits into each class of passages, and the colours are carried to the sight by effluence. R. P. ib.

But eyes are not all composed in the same way; some are composed of like elements and some of opposite; some have the fire in the centre and some on the outside. That is why some animals are keen-sighted by day and others by night. Those which have less fire are keen-sighted in the daytime, for the fire within is brought up to an equality by that without; those which have less of the opposite (i.e. water), by night, for then their deficiency is supplemented. But, in the opposite case, each will behave in the opposite manner. Those eyes in which fire predominates will be dazzled in the daytime, since the fire being still further increased will stop up and occupy the pores of the water. Those in which water predominates will, he says, suffer the same at night, for the fire will be obstructed by the water. And this goes on till the water is separated off by the air, for in each case it is the opposite which is a remedy. The best tempered and the most excellent vision is one composed of both in equal proportions. This is practically what he says about sight.

Hearing, he holds, is produced by sound outside, when the air moved by the voice sounds inside the ear; for the sense of hearing is a sort of bell sounding inside the ear, which he calls a "fleshy sprout." When the air is set in motion it strikes upon the solid parts and produces a sound.133 Smell, he holds, arises from respiration, and that is why those smell most keenly whose breath has the most violent motion, and why most smell comes from subtle and light bodies.134 As to touch and taste, he does not lay down how, nor by means of what they arise, except that he gives us an explanation applicable to all, that sensation is produced by adaptation to the pores. Pleasure is produced by what is like in its elements and their mixture; pain, by what is opposite. R. P ib.

And he gives a precisely similar account of thought and ignorance. Thought arises from what is like and ignorance from what is unlike, thus implying that thought is the same, or nearly the same, as perception. For after enumerating how we know each thing by means of itself, he adds, "for all things are fashioned and fitted together out of these, and it is by these men think and feel pleasure and pain" (fr. 107). And for this reason we think chiefly with our blood, for in it of all parts of the body all the elements are most completely mingled. R. P. 178.

All, then, in whom the mixture is equal or nearly so, and in whom the elements are neither at too great intervals nor too small or too large, are the wisest and have the most exact perceptions; and those who come next to them are wise in proportion. Those who are in the opposite condition are the most foolish. Those whose elements are separated by intervals and rare are dull and laborious; those in whom they are closely packed and broken into minute particles are impulsive, they attempt many things and finish few because of the rapidity with which their blood moves. Those who have a well-proportioned mixture in some one part of their bodies will be clever in that respect. That is why some are good orators and some good artificers. The latter have a good mixture in their hands, and the former in their tongues, and so with all other special capacities. R. P. ib.

Perception, then, is due to the meeting of an element in us with the same element outside. This takes place when the pores of the organ of sense are neither too large nor too small for the "effluences" which all things are constantly giving off (fr. 89). Smell was explained by respiration. The breath drew in along with it the small particles which fit into the pores. Empedokles proved this by the example of people with a cold in their head,135 who cannot smell, just because they have a difficulty in breathing. We also see from fr. 101 that the scent of dogs was referred to in support of the theory. Empedokles seems to have given no detailed account of smell, and did not refer to touch at all.136 Hearing was explained by the motion of the air which struck upon the cartilage inside the ear and made it swing and sound like a bell.137

The theory of vision138 is more complicated; and, as Plato makes his Timaios adopt most of it, it is of great importance in the history of philosophy. The eye was conceived, as by Alkmaion (§ 96),139 to be composed of fire and water. Just as in a lantern the flame is protected from the wind by horn (fr. 84); so the fire in the iris is protected from the water which surrounds it in the pupil by membranes with very fine pores, so that, while the fire can pass out, the water cannot get in. Sight is produced by the fire inside the eye going forth to meet the object.

Empedokles was aware, too, that "effluences," as he called them, came from things to the eyes as well; for he defined colours as "effluences from forms (or 'things') fitting into the pores and perceived."140 It is not quite clear how these two accounts of vision were reconciled, or how far we are entitled to credit Empedokles with the theory of Plato's Timaeus. The statements quoted seem to imply something very like it.141

Theophrastos tells us that Empedokles made no distinction between thought and perception, a remark already made by Aristotle.142 The chief seat of perception was the blood, in which the four elements are most evenly mixed, and especially the blood near the heart (fr. 105).143 This does not, however, exclude the idea that other parts of the body may perceive also; indeed, Empedokles held that all things have their share of thought (fr. 103). But the blood was specially sensitive because of its finer mixture.144 From this it naturally follows that Empedokles adopted the view, already maintained in the Second Part of the poem of Parmenides (fr. 16), that our knowledge varies with the varying constitution of our bodies (fr. 106).

Burnet's Notes


132. That is watery vapour, not the elemental air or αἰθήρ (§ 107). It is identical with the "water" mentioned below. It is unnecessary, therefore, to insert καὶ ὕδωρ after πῦρ with Karsten and Diels.

133. Beare, p. 96 n. 1.

134. Ibid. p. 133.

135. Aet. iv. 17, 2 (Dox. p. 407). Beare, p. 133.

136. Beare, pp. 161-3, 180-81.

137. Ibld. pp. 95 sqq.

138. Ibid. pp. 14 sqq.

139. Theophr. De sens. 26.

140. The definition is quoted from Gorgias in Plato, Men. 76 d 4. All our MSS. have ἀπορροαὶ σχημάτων, but Ven. T has in the margin γρ. χρημάτων, which may well be an old tradition. The Ionic for "things" is χρήματα. See Diels, Empedokles und Gorgias, p. 439.

141. See Beare, Elementary Cognition, p. 18.

142. Arist. De an. Γ, 3. 427 a 21.

143. R. P. 178 a. This was the characteristic doctrine of the Sicilian school, from whom it passed to Aristotle and the Stoics. Plato and Hippokrates, on the other hand, adopted the view of Alkmaion (§ 97) that the brain was the seat of consciousness. At a later date, Philistion of Syracuse, Plato's friend, substituted the ψυχικὸν πνεῦμα ("animal spirits") which circulated along with the blood.

144. Beare, p. 253.

Created for Peithô's Web from Early Greek Philosophy by John Burnet, 3rd edition (1920). London: A & C Black Ltd. Burnet's footnotes have been converted to chapter endnotes. Greek unicode text entered with Peithô's Younicoder.
Web design by Larry Clark and RSBoyes (Agathon). Peithô's Web gratefully acknowledges the assistance of Anthony Beavers in the creation of this web edition of Burnet. Please send comments to:
agathon at classicpersuasion