A key question for the ancient Greeks (as it still is for many people today) is whether the soul can exist independently of the body. Anyone who believes in immortality also believes in the independent existence of the soul. Plato certainly thought that the soul could exist separately. Here is what Aristotle has to say on this topic:
. . . the soul does not exist without a body and yet is not itself a kind of body. For it is not a body, but something which belongs to a body (414a20ff).
So according to Aristotle the soul is not separable from the body. If the soul is what gives the body its form, bringing it forth as a living individual, then we need to recognise just how close the relationship between body and soul becomes. We do not have a body, with its own form and performing its own actions, to which a secondary, invisible thing called a ‘soul’ is added. The term soul describes that which shapes and gives life to the body.
Furthermore according to Aristotle the soul is the form and shape of the body: “and for this reason the soul exists in a body, and in a body of such-and-such a kind.” The soul is not a substance like matter because matter can be given Form and be many different things. The soul gives shape to the matter which is the body. The soul is the principle of life or activity of the body. There is no hidden, secret you, distinct from all that you actually think and say and do. There is no separate, detached soul.
The shorthand way of describing Aristotle's view of the soul and its relationship to the body, is to say that the soul of an axe is cutting, the soul of an eye is seeing, and the soul of a man is thinking. In other words, everything has a form or an essence, which is shown in its primary activity. The soul is what makes a thing what it is.
It comes as no surprise then that in De Anima Aristotle links his ideas about the soul with his Four Causes: The soul is the cause and principle of the