proved to be of fundamental importance for the method of science. For example, it led Einstein, as he himself admits, to the discovery of the Theory of Relativity. It may be empirically impossible to follow those prescriptions (like travelling around the moon), but it cannot be logically impossible. For what is logically impossible cannot even be described, i. e., it cannot be expressed by words or other means of communication.
The truth of this last statement is shown by an analysis of "description" and "expression" into which we cannot enter here. But taking it for granted, We see that no real question is in principle — i. e. logically — unanswerable. For the logical impossibility of solving a problem is equivalent to the impossibility of describing a method of finding its solution; and this, as we have stated, is equivalent to the impossibility of indicating the meaning of the problem. Thus a question which is unanswerable in principle can have no meaning, it can be no question at all : it is nothing but a nonsensical series of words with a question mark after them. As it is logically impossible to give an answer where there is no question, this cannot be a cause of wonder, dissatisfaction, or despair.
This conclusion can be made clearer by considering one or two examples. Our question as to the weight of Homer has meaning, of course, because we can easily describe methods of weighing human bodies (even poets); in other words, the notion of weight is accurately defined. Probably Homer was never weighed, and it is empirically impossible to do it now, because his body no longer exists; but these accidental facts do not alter the sense of the question.
Or take the problem of survival after death. It is a meaningful question, because we can indicate ways in which it could be solved. One method of ascertaining one's own survival would simply consist in dying. It would also be possible to describe certain observations of scientific character that would lead us to accept a definite answer. That such observations could not be made thus far is an empirical fact which cannot entail a definite ignorabimus in regard to the problem.
Now consider the question: "What is the nature of time?" What does it mean? What do the words "the nature of" stand for? The scientist might, perhaps, invent some kind of explanation, he might suggest some statements which he would regard as possible answers to the question ; but his explanation
