Of these three points the last is the most definite. Let us take it first; and let us take it as stated, not by a professed socialist, but by an independent and highly educated thinker such as Mr. Kidd. Mr. Kidd's argument is, as we have seen already, that the comparative commonness of ability of the highest kind is shown by the fact that, of the greatest inventions and discoveries, a number have been notoriously made at almost the same time by a number of thinkers who have all worked in isolation. This argument would not be worth discussing if it were not used so constantly by a variety of serious writers. The fact on which it bases itself is no doubt true enough; but what is the utmost that it proves? That more men than one should reach at the same time the same discovery independently is precisely what we should be led to expect, when we consider what the character of scientific discovery is. The facts of nature which form its subject-matter are in themselves as independent of the men who discover them as an Alpine peak is of the men who attempt to climb it. They are, indeed, precisely analogous to such a peak which all discoverers are attempting to scale at once; and the fact that three men make at once the same discovery does no more to show that it could have been made by the majority of their fellow-workers, and that it was in reality made not by themselves but by their generation, than the fact that three men of exceptional nerve and endurance meet at last on some previously virgin summit proves the feat to have been accomplished less by these men themselves than by the mass of tourists who thronged the hotel below and whose climbing exploits were limited to an ascent by the Rigi Railway.