All this confirms in the most striking way the statement of Theophrastos, that Anaxagoras had belonged to the school of Anaximenes. The flat earth floating on the air, the dark bodies below the moon, the explanation of the solstices and the “turnings” of the moon by the resistance of air, the explanations given of wind and of thunder and lightning, are all derived from the earlier inquirer. [Sidenote: Biology.] 136. “There is a portion of everything in everything except Nous, and there are some things in which there is Nous also” (fr. 11). In these words Anaxagoras laid down the distinction between animate and inanimate things. He tells us that it is the same Nous that “has power over,” that is, sets in motion, all things that have life, both the greater and the smaller (fr. 12). The Nous in living creatures is the same in all (fr. 12), and from this it followed that the different grades of intelligence which we observe in the animal and vegetable worlds depend entirely on the structure of the body. The Nous was the same, but it had more opportunities in one body than another. Man was the wisest of animals, not because he had a better sort of Nous, but simply because he had hands.[718] This view is quite in accordance with the previous development of thought upon the subject. Parmenides, in the Second Part of his poem (fr. 16), had already made the thought of men depend upon the constitution of their limbs. As all Nous is the same, we are not surprised to find that plants were regarded as living creatures. If we may trust the pseudo-Aristotelian _Treatise on Plants_[719] so far, Anaxagoras argued that they must feel pleasure and pain in connexion with their growth and with the fall of their leaves. Plutarch says[720] that he called plants “animals fixed in the earth.” Footnote 718: Arist. _de Part. An._ Δ, 10. 687 a 7 (R. P. 160 b). Footnote 719: [Arist.] _de plant._ Α, 1. 815 a 15 (R. P. 160). Footnote 720: Plut. _Q.N._ 1 (R. P. 160), ζῷον ... ἐγγεῖον. Both plants and animals originated in the first instance from the πανσπερμία. Plants first arose when the seeds of them which the air contained were brought down by the rain-water,[721] and animals originated in a similar way.[722] Like Anaximander, Anaxagoras held that animals first arose in the moist element.[723] Footnote 721: Theophr. _Hist. Plant._ iii. 1, 4 (R. P. 160). Footnote 722: Irenaeus, _adv. Haer._ ii. 14, 2 (R. P. 160 a). Footnote 723: Hipp. _Ref._ i. 8, 12 (_Dox._ p. 563). 137. In these scanty notices we seem to see traces of a polemical attitude towards Empedokles, and the same may be observed in what we are told of the theory of perception adopted by Anaxagoras, especially in the view that perception is of contraries.[724] The account which Theophrastos gives of this[725] is as follows:—