This ambiguity, then, is all the more conspicuous in the case of symbolical representation for the reason that an image, which carries a particular significance, only receives the descriptive name of _symbol_ when such significance ceases to be expressly marked by itself, or is otherwise clearly emphasized as it is in the case of the simile. No doubt the ambiguity of the genuine symbol is to this extent removed in that by virtue of this very uncertainty the fusion of the sensuous image and its significance becomes a matter more or less of convention and custom, a feature which is indispensably necessary in the case where mere signs are used, while on the other hand the simile asserts itself as something individual, discovered on the spur of the moment to assist the meaning, and is independently clear, because it emphasizes the significance alongside of that independence. At the same time, though no doubt the symbol may be clear enough to those who are habituated to its use, and whose imaginative life is at home in such a conventional atmosphere, it is a very different matter with all who are outside this native circle, or for whom it is now a thing of the Past; for such it is only the immediate sensuous representation which is in the first instance seized, and it remains for these in every way a question of doubt, whether they are to rest satisfied with that which lies openly before their eyes, or are to accept these as indicators to yet further imagery or ideas. When, for example, we gaze in Christian churches upon the _triangle_ in some conspicuous position on the walls, we at once recognize that the intention is not to place before the view this geometrical figure simply as such, but rather to draw our attention to its spiritual significance. If, however, we were to find it elsewhere we should probably feel equally certain that such a figure had no reference whatever, either as sign or symbol, to the Trinity. On the other hand a folk strange to the ideas which have grown up in Christian countries might easily feel doubts in both cases, and it is by no means easy for ourselves to determine with equal certainty in all cases, whether a figure of this kind is to be understood as presenting us with its literal or symbolical interpretation.