i. 80. 2

answer that, We must needs say that the intellectual appetite is a distinct power from the sensitive appetite. For the appetitive power is a passive power, which is naturally moved by the thing apprehended: wherefore the apprehended appetible is a mover which is not moved, while the appetite is a mover moved, as the Philosopher says in De Anima iii, 10 and Metaph. xii (Did. xi, 7). Now things passive and movable are differentiated according to the distinction of the corresponding active and motive principles; because the motive must be proportionate to the movable, and the active to the passive: indeed, the passive power itself has its very nature from its relation to its active principle. Therefore, since what is apprehended by the intellect and what is apprehended by sense are generically different; consequently, the intellectual appetite is distinct from the sensitive.