true that when those words are heard or read, the thoughts in question _generally_ have existed. If when those words were heard or read, the thoughts had generally _not_ existed, we should say that, in one sense of the word at all events, the hearing of the words was _not_ a sign of the existence of the thoughts. In this sense, therefore, to say that the existence of A "points to" or "is a sign of" the existence of B is actually to say that when A exists, B _generally_ exists also. But, no doubt, the words "points to" "is a sign of" may be used in some other sense: they may, for instance, mean only that the existence of A _suggests_ in some way the belief that B exists. And in such a case we certainly might know that the existence of A pointed to the existence of B, without knowing that when A existed B generally existed also. Let us suppose, then, that in some such sense A does "point to" the existence of B; can this fact give us a reason for supposing it even probable that B existed. Certainly it can, _provided_ it is true that when A _does_ point to the existence of B, B _generally_ exists. But surely it can do so, only on this condition. If when A _points_ to the existence of B, B, nevertheless, does _not_ generally exist, then surely the fact that A points to the existence of B can constitute no probability that B does not exist: on the contrary it will then be probable that, even though A "points to" the existence of B, B does _not_ exist. We have, in fact, only substituted the generalisation that A's _pointing to_ B is generally accompanied by the existence of B, for the generalisation that A's _existence_ is generally accompanied by the existence of B. If we are to have any reason for asserting that, when A _points to_ or is a sign of the existence of B, B probably exists, we must still have a reason for some generalisation--for a generalisation which asserts that when one thing points to the existence of another, that other _generally_ exists.