The perceptive act is a reaction of the mind upon the object of which it is the perception.
Samuel AlexanderThus the same object may supply a practical perception to one person and a speculative one to another, or the same person may perceive it partly practically and partly speculatively.
Samuel AlexanderDesire then is the invasion of the whole self by the wish, which, as it invades, sets going more and more of the psychical processes; but at the same time, so long as it remains desire, does not succeed in getting possession of the self.
Samuel Alexander