"The main reason I have not sent you a question is that I can not think of one worth sending. So maybe my appropriate question is 'What question should I ask?' The one I wish I could identify would be of great intellectual or practical interest, and I (or someone) would have some hope of solving it. Peter Medawar once defined science as 'the art of the soluble'. This is an example of a definition that may be formally correct but does not help anyone trying to find out what science is, but it makes a good point. For a problem to be scientifically important it has to be soluble. How many angels can dance on a pinhead may be a problem of great interest to some people, but it is not soluble."