I am aware that this is by no means a perfect word for my purpose, since, on the one hand, it suggests that every form of this knowledge must be less certain than presentative or mnemonic knowledge, which cannot be assumed; and since, on the other hand, the word is so useful a one in psychology, for the purpose of marking off the subjective fact of assurance in all kinds of cognition.
Nevertheless, I know not what better one I could select in order to make my classification answer as closely as a scientific treatment will allow to the deeply fixed distinctions of popular psychology.
It might at first seem as if perception, introspection, and memory must exhaust all that is meant by immediate, or self-evident, knowledge, and as if what I have here called belief must be uniformly mediate, derivate, or inferred knowledge.

The apprehension of something now present to the mind, externally or internally, and the reapprehension through the process of memory of what was once so apprehended, might appear to be the whole of what can by any stretch of language be called direct cognition of things.

This at least would seem to follow from the empirical theory of knowledge, which regards perception and memory as the ground or logical source of all other forms of knowledge.
And even if we suppose, with some philosophers, that there are certain innate principles of knowledge, it seems now to be generally allowed that these, apart from the particular facts of experience, are merely abstractions; and that they only develop into complete knowledge when they receive some empirical content, which must be supplied either by present perception or by memory.

So that in this case, too, all definite concrete knowledge would seem to be either presentative cognition, memory, or, lastly, some mode of inference from these.
A little inquiry into the mental operations which I here include under the name belief will show, however, that they are by no means uniformly process of inference.

To take the simplest form of such knowledge, anticipation of some personal experience: this may arise quite apart from recollection, as a spontaneous projection of a mental image into the future.