…there are three elements of cognition; thoughts, the habitual connection between thoughts, and processes establishing a habitual connection between thoughts. We have seen already that an idea cannot be instantaneously present, that consciousness occupies time, and that we have no consciousness in an instant. So that at no time have we a thought. But now it further appears that in reference to a belief not only can we not have it in an instant, but it can not be present to the mind in any period of time. It does not consist in anything which is present to the mind, but in an habitual connection among the things which are successively present. That is to say, it consists in ideas succeeding one another according to a general rule; but not in the mere thinking of this general rule, nor in the mere succession of ideas one upon another, nor in both together. A thought must therefore be a sign of a belief; but is never the belief itself. The same thing is obviously true in regard to an inference; and even a simple idea is of intellectual value to us not for what it is in itself but as standing for some object to which it relates. Now a thing which stands for another thing is a representation or sign. So that it appears that every species of actual cognition is of the nature of a sign.
…cognition is a consciousness of a sign, and is a triple consciousness of the sign, of the real object cognized, and of the meaning, or interpretation, of the sign which the cognition connects with the object.