In the second place, according to ‘Abd al-Latif, Avicenna seems to have distorted or not to have had any knowledge of the fundamental Aristotelian epistemological criterion according to which research must begin with that which is more easily knowable to us (cf. Aristotle, Physics I.1, 184a16–21; Nicomachean Ethics I.4, 1095b3–4). This is why, for example Avicenna mistakenly placed zoology after his treatment of the soul.