  With regard to psychology, Telesio took a materialist standpoint. According to his general rejection of the metaphysical (and therefore inappropriate) principles of matter and form, he rejected Aristotle's definition of the soul as forma corporis, i.e. as form and entelechy of an organic body (Aristotle, De anima II,1). According to Telesio, the soul is a separate being, but not in the sense of the Platonists, who define it as an immortal essence acting as the governor and mover of the body during its embodied life. Telesio held the soul to be a specific part of the body, defining it as the spiritus coursing through the nervous system and having its main seat in the brain. The spiritus which overtakes the role of the anima of the philosophical tradition is produced by the white ‘semen’. Telesio calls it the spiritus e semine eductus. He maintains in DRN book V, ch. I: