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INSTITUTES OF METAPHYSIC.
PROP. III.————
relation, the word "external" has, and can have, no meaning.
The unit of cognition explained. How it is determined.5. The unit or minimum of cognition is such an amount (and no more) of cognition as can be known. The knowable must mount up to a certain point before it can become the knowable least. In this respect the magnitude of the knowable is quite different from visible or ponderable magnitude. The visible or ponderable least cannot be determined absolutely, because there is no necessary law of reason fixing it. It is a varying quantity contingent on the capacities of the seer or the weigher. But the knowable least is determined absolutely by an essential law of all intelligence; it cannot be less than some thing or thought, with the addition of oneself. It cannot be less than object + subject; because anything less than this is absolutely unknowable by a necessary law of reason. No necessary law of knowledge fixes that the capacity of seeing or hearing or weighing shall not go below a certain limit: because with finer organs or with finer instruments a new minimum of sight or of sound or of weight might, for ever and ever, be revealed. But the capacity of knowing is sternly and everlastingly, and universally prohibited from going below a certain limit: it cannot descend to the apprehension of less than object + subject. This, therefore, is the least, the ultimate that can be
