We may very likely find also in a similar notion the explanation of a peculiarity often found in early statues of the gods--the well-known archaic smile. Many explanations, technical and otherwise, have been given of this device; but none of them can get over the fact that it was just as easy, or even easier, for a primitive sculptor to make the mouth straight as to make it curve up at the ends, and that he often did make it straight. When he does not do so, it is probably done with intention; and it is quite in accordance with the conditions of early religious art that he should make the image of a deity smile in order that the deity himself might smile upon his worshippers; and a pleasant expression might also, by a natural transfer of ideas, be supposed to be pleasing to the god, and so attract him to his statue. We are told that at Chios there was a head of Artemis set high up, which appeared morose to those entering the temple, but when they left it seemed to have become cheerful. This may have been originally due to some accident of placing or lighting, but it seems to have acquired a religious significance; and we can hardly deny a similar significance to the smile which we find on so many early statues. In some cases, especially in statues of men, it may have been intended merely as a device to give expression and life to the face; but it cannot have been a matter of indifference to a primitive worshipper that his deity should smile on him through the face of its visible image. This point of view being given, it is evidently only a question of how far it is within the power of art to express the benignity of the god, and later on his character and personality, in an adequate manner; and this power depends on the gradual acquisition of mastery over form and material, of knowledge and observation of the human body and face, and of the technical skill requisite to express this knowledge in marble or bronze, or more precious materials such as gold and ivory. All this development belongs to the history of art, not to that of religion. But before we can pursue the investigation any further, it is necessary to consider the different sources and channels of religious influence on art with which we have to deal. CHAPTER II VARIOUS ASPECTS OF RELIGION Religion, for our present purpose, may be considered as (1) popular, (2) official, (3) poetic, and (4) philosophical. These four divisions, or rather aspects, are not, of course, mutually exclusive, and they act and react extensively upon one another; but, in their relations to art, it is convenient to observe the distinction between them.