For simplicity's sake, I have written as if my main problem were to show how, in the face of a supposed difficulty, a strictly realistic theory of the perceptual event may be maintained. But my interest is primarily in the facts, and in the theory only because of the facts it formulates. The significance of the facts of the case may, perhaps, be indicated by a consideration which has thus far been ignored. In regarding a perception as a case of knowledge, the presentative realist does more than shove into it a relation to mind which then, naturally and inevitably, becomes the explanation of any differences that exist between its subject-matter and some causal object with which it contrasts. In many cases--very important cases, too, in the physical sciences--the contrasting "real object" becomes known by a logical process, by inference--as the contemporary position of the star is determined by calculations from data, not by perception. This, then, is the situation of the presentative realist: If perception is knowledge of its cause, it stands in unfavorable contrast with another indirect mode of knowledge; _its_ object is less valid than the object of inference. I do not adduce these considerations as showing that the case is hopeless for the presentative realist;[61] I am willing to concede he can find a satisfactory way out. But the difficulty exists; and in existing it calls emphatic attention to a case which is certainly and indisputably a case of knowledge--namely, propositions arrived at through inference, judgments as logical assertions.