Now if we take the most parallel case to this which we can find, and consider what we should ourselves do under such circumstances, that is to say, if we consider what course is actually taken by beings who are influenced by what we all call memory, when they repeat an already often-repeated performance, and if we find a very strong analogy between the course so taken by ourselves, and that which from whatever cause we observe to be taken by a living germ, we shall surely be much inclined to think that there must be a similarity in the causes of action in each case; and hence, to conclude, that the action of the germ is due to memory. It will, therefore, be necessary to consider the general tendency of our minds in regard to impressions made upon us, and the memory of such impressions. Deep impressions upon the memory are made in two ways, differing rather in degree than kind, but with two somewhat widely different results. They are made:— I. By unfamiliar objects, or combinations, which come at comparatively long intervals, and produce their effect, as it were, by one hard blow. The effect of these will vary with the unfamiliarity of the impressions themselves, and the manner in which they seem likely to lead to a further development of the unfamiliar, _i.e._, with the question, whether they seem likely to compel us to change our habits, either for better or worse. Thus, if an object or incident be very unfamiliar, as, we will say, a whale or an iceberg to one travelling to America for the first time, it will make a deep impression, though but little affecting our interests; but if we struck against the iceberg and were shipwrecked, or nearly so, it would produce a much deeper impression, we should think much more about icebergs, and remember much more about them, than if we had merely seen one. So, also, if we were able to catch the whale and sell its oil, we should have a deep impression made upon us. In either case we see that the amount of unfamiliarity, either present or prospective, is the main determinant of the depth of the impression. As with consciousness and volition, so with sudden unfamiliarity. It impresses us more and more deeply the more unfamiliar it is, until it reaches such a point of impressiveness as to make no further impression at all; on which we then and there die. For death only kills through unfamiliarity—that is to say, because the new position, whatever it is, is so wide a cross as compared with the old one, that we cannot fuse the two so as to understand the combination; hence we lose all recognition of, and faith in, ourselves and our surroundings.