 According to Simon, the intellect is the faculty of the rational soul whereby it thinks. Simon, who follows the Aristotelian doctrine closely, holds this faculty to be immaterial, passive, and separate. It is separate because it does not need to use an organ in order to perform its operation of intellection. It is also passive, but not in the same sense matter is passive. In fact, there are two senses in which something is passive: it can receive forms with or without undergoing qualitative change. Like matter, the intellect receives forms because it needs an intelligible object on which to perform its proper operation. But matter is passive in a further and more fundamental sense: when brought to act by a form, it suffers qualitative change. The intellect, however, does not suffer qualitative change, but is simply actualized. Accordingly, the intellect is passive simply because it is potential with respect to the act of intellection. And precisely because it does not suffer qualitative change when it is brought to act, the intellect is also said to be immaterial.