constituent of this experience is the appearance of a certain perception (of food in our example), the memory picture of which thereafter remains associated with the memory trace of the excitation of want.

Thanks to the established connection, there results at the next appearance of this want a psychic feeling which revives the memory picture of the former perception, and thus recalls the former perception itself, i.e. it actually re-establishes the situation of the first gratification. We call such a feeling a wish; the reappearance of the perception constitutes the wish-fulfillment, and the full revival of the perception by the want excitement constitutes the shortest road to the wish-fulfillment. We may assume a primitive condition of the psychic apparatus in which this road is really followed, i.e.