=268.= The soul in its substance or stuff is fire, identical with the creative fire which is the primal stuff of the universe[21]. But the popular conception, according to which the soul is air or breath, and is seen to leave the body at death, is also not without truth[22]. There is a very general opinion that the soul is a mixture of fire and air, or is hot air[23]. By this a Stoic would not mean that the soul was a compound of two different elements, but that it was a variety of fire in the first stage of the downward path, beginning to form air by relaxation of its tension: but even so this form of the doctrine was steadily subordinated to the older doctrine of Heraclitus, that the soul is identical with the divine fire. Formally the soul is defined, like the deity himself, as a ‘fiery intelligent spirit[24]’; and in this definition it would seem that we have no right to emphasize the connexion between the word ‘spirit’ (πνεῦμα) and its original meaning ‘breath,’ since the word has in our philosophy many other associations. It is further a Stoic paradox that ‘the soul is an animal,’ just as God is an animal. But the soul and the man are not on that account two animals; all that is meant is that men and the brutes, by reason of their being endowed with soul, become animals[25]. [Sidenote: The temperaments.] =269.= According to another theory, which is probably not specifically Stoic, but derived from the Greek physicians, the soul is compounded of all four elements in varying proportion, and the character of each soul (subject, in the Stoic theory, to the supreme control of reason[26]) is determined by the proportion or ‘temperament’ (κρᾶσις, _temperatura_) of the four elements. There are accordingly four temperaments, the fervid, the frigid, the dry, and the moist, according to the preponderance of fire, air, earth, and water respectively[27]. Dull and sleepy natures are those in which there is an excess of the gross elements of earth and water[28]; whilst an excess of cold air makes a man timorous, and an excess of fire makes him passionate[29]. These characters are impressed upon a man from birth and by his bodily conditions, and within the limits indicated above are unalterable[30]. The ‘temperaments’ have always been a favourite subject of discussion in popular philosophy[31]. [Sidenote: The soul’s parts.]