In all such cases it would perhaps be a more satisfactory mode of speech to say that we do not in fact have any knowledge of the person, thing, or conceptual structure in question. We do not know Julius Caesar; we only imagine what kind of happenings probably occurred in his life. We do not actually see the other side of the moon; we only see a photographic emulsion on which the light and dark shading is

reasonably taken as copying other shadings reasonably taken as caused by light reflected from the surface of the moon; and so with the other examples. In what sense, then, can we have 'indirect' knowledge of the inner constitution of nature? Do we only imagine the sort of existence or conditions which might reasonably be supposed to be constituted 'behind the scenes'? In that case, what is the kind of 'reason' to which we are appealing?