Conceptions are distinguished into two classes with reference to this one fact, that some of our conceptions are attended with a consciousness that they have existed before, and others are not. Those conceptions which are thus attended with the feeling of their resemblance to past perceptions or conceptions are called ideas of _memory_; those of our _perceptions_ also which are attended with this recognition are called memory.
How important to our happiness and improvement is this recognition of past ideas, few are wont to imagine. If all our knowledge of external things were forever lost to us after sensation is past, our existence would be one of mere sensitive enjoyment, and all the honor and dignity of mind would be destroyed. No past experience could be of any avail, nor could any act of judgment or of reasoning be performed. Even the most common wants of animal nature could not be supplied; for, were the cooling water and sustaining food presented to the sight, no memory of the past comfort secured by them would lead the mind to seek it again. Or, had nature, by some implanted instinct, provided for these necessities, yet life in this case would have consisted of a mere succession of sensations, without even the amount of intellect of which the lower animals give proof.
It is the capacity of retrospection, too, which gives us the power of foreseeing the future, and thus of looking both before and behind for sources of enjoyment in delightful reminiscences and joyful anticipations. It is this power of remembrance and foresight which raises man to be the image of his Creator, the miniature of Him who sees the end from the beginning, who looks back on never commencing ages, and forward through eternal years.
It is true the mind of man can foresee only by the process of reasoning, by which it is inferred that the future will, in given circumstances, resemble the past. And how the Eternal Mind can foresee by intuition all the events which hang upon the volitions of the myriads of acting minds which he has formed is what no human intellect can grasp. The _foresight of intuition_ has not been bestowed upon man, but is reserved as one distinctive prerogative of Deity.