It has been pointed out that St. Albert the Great, in defining the human soul as it is in itself, turns to Avicenna rather than to Aristotle. There is, he says, a twofold definition of the human soul, one in relation to the body according as it is the act and mover of a body, and one in itself according as it is a substance. And it is better to speak of the soul as a perfection than as a form, (...) since forma signifies something essentially related to matter, whereas perfectio does not; and the soul, as substance, can subsist without a body as a sailor can without a ship. Indeed, the only difference between the soul and an angel is that the soul ‘is inclined’ to a body as its act, whereas an angel is not. The Aristotelian definition of the soul as form has application to the soul in its relation to the body; but to express what the soul is in itself we must turn to the Avicennian definition of the soul as perfection. (shrink)