Let us assume that a being with fully developed human intelligence originated out of nothing and confronted the world. All that it there perceived before its thought began to act would be the pure content of perception. The world so far would appear to this being as a mere chaotic aggregate of sense-data, colours, sounds, sensations of pressure, of warmth, of taste, of smell, and, lastly, feelings of pleasure and pain. This mass constitutes the world of pure unthinking perception. Over against it stands thought, ready to begin its activity as soon as it can find a point of attack. Experience shows that the opportunity is not long in coming. Thought is able to draw threads from one sense-datum to another. It brings definite concepts to bear on these data and thus establishes a relation between them. We have seen above how a noise which we hear is connected with another content by our identifying the first as the effect of the second. If now we recollect that the activity of thought is on no account to be considered as merely subjective, then we shall not be tempted to believe that the relations thus established by thought have merely subjective validity. Our next task is to discover by means of thought what relation the above-mentioned immediate sense-data have to the conscious subject. The ambiguity of current speech makes it advisable for me to come to an agreement with my readers concerning the meaning of a word which I shall have to employ in what follows. I shall apply the name "percepts" to the immediate sense-data enumerated above, in so far as the subject consciously apprehends them. It is, then, not the process of perception, but the object of this process which I call the "percept." I reject the term "sensation," because this has a definite meaning in Physiology which is narrower than that of my term "percept." I can speak of feeling as a percept, but not as a sensation in the physiological sense of the term. Before I can have cognisance of my feeling it must become a percept for me. The manner in which, through observation, we gain knowledge of our thought-processes is such that when we first begin to notice thought, it too may be called a percept.