The conditions under which non-logical conduct _becomes_ logical are familiar to those who have followed the doctrines of experimental logic as expounded in the discussions of the past few years. The transformation begins at the point where non-logical processes instead of operating as direct unambiguous stimuli and response become ambiguous with consequent inhibition of conduct. But again this does not mean that at this juncture the non-logical processes quit the field and give place to a totally new faculty and process called reason. They stay on the job. But there is a change in the job, which now is to get rid of this ambiguity. This modification of the task requires, of course, corresponding modification and adaptation of these operations. They take on the form of sensations and universals, terms and relations, data and hypotheses. This modification of function and form constitutes "reason" or, better, reasoning. Here some one will ask, "Whence comes this ambiguity? How can a mere perception or memory as such be ambiguous? Must it not be ambiguous to, or for, something, or some one?" The point is well taken. But it should not be taken to imply that the ambiguity is for a merely onlooking, beholding psychical mind--especially when the perception is itself regarded as an act of beholding. Nor are we any better off if we suppose the beholding mind to be equipped with a faculty of reason in the form of the principle of "contradiction." For this throws no light on the origin and meaning of ambiguity. And if we seek to make all perceptions as such ambiguous and contradictory, in order to make room for, and justify, the operations of reason, other difficulties at once beset us. When we attempt to remove this specific ambiguity of perceptive conduct we shall be forced, before we are through, to appeal back to perception, which we have condemned as inherently contradictory, both for data and for verification. However, the insistence that perception must be ambiguous to, or for, something beyond itself is well grounded. And this was recognized in the statement that it is equivocal as a stimulus in conduct. There need be no mystery as to how such equivocation arises. That there is such a thing as a conduct at all means that there are certain beings who have acquired definite ways of responding to one another. It is important to observe that these forms of interaction--instinct and habit, perception, memory, etc.--are not to be located in either of the interacting beings but are functions of both. The conception of these operations as the private functions of an organism is the forerunner of the epistemological predicament. It results in a conception of knowing as wholly the act of a knower apart from the known. This is the beginning of epistemology.