answer; we are confronted with an "insolvable problem". This is the only case of an "absolutely unanswerable" question: it is unanswerable, because it is no question. It may look like one, because outwardly it has the grammatical form of a question, but in reality it is a meaningless series of words, followed by a question mark.
Now we understand the nature of the so-called insolvable problem about which philosophers have worried so much: they are insolvable not because their solution lies in a region forever inaccessible to the knowing mind, not because they pass the power of our understanding, but simply because they are no problems.
Unfortunately — no, fortunately — all genuine "metaphysical questions" turn out to be of this kind. Metaphysics, as we stated before, consists essentially in the attempt to express content, i.e. in a self-contradictory enterprise, but it is by no means easy to see that a question inquiring into the nature of content is nothing but a meaningless arrangement of words. The difficulty of perceiving this is the real cause of all the troubles from which philosophical speculation has been suffering for about twenty-five centuries. If the nonsense in the typical metaphysical issues had been as easy to detect as the lack of meaning (say) in the question, "Is time more logical than space?" most of the futile discussions of our great thinkers could have been avoided.
The situation is made more complex by the fact, that in many cases the verbal formulation of the doubtful issues admits of two interpretations: one in which the words (or at least one of them) stand for content — and in this case the sentence expresses nothing — and another one in which the whole can be regarded as a structure complying with the rules of logical grammar: in this case the issue is changed into a real scientific question which must be answered by observation and experiment, the ordinary methods of experience (only the second interpretation, of course, is really an interpretation, the first one gives a semblance of meaning only).
An instructive example of the situation is afforded by the formulations which are supposed to express the metaphysical positions of idealism and materialism. In my last lecture I have treated the sentence "The internal nature of everything is Mind (or Matter)" as a metaphysical assertion in which the word Mind (or Matter) was supposed to signify content, and I have
