There are no solved problems; there are only problems that are more or less solved. — Henri Poincare Copy Share Image
Logic sometimes makes monsters. For half a century we have seen a mass of bizarre functions which appear to be forced to… — Henri Poincare Copy Share Image
It is by logic that we prove, but by intuition that we discover. To know how to criticize is good, to know… — Henri Poincare Copy Share Image
Pure logic could never lead us to anything but tautologies; it can create nothing new; not from it alone can any science… — Henri Poincare Copy Share Image
What is a good definition? For the philosopher or the scientist, it is a definition which applies to all the objects to… — Henri Poincare Copy Share Image
When the logician has resolved each demonstration into a host of elementary operations, all of them correct, he will not yet be… — Henri Poincare Copy Share Image
It is with logic that one proves; it is with intuition that one invents. — Henri Poincare Copy Share Image
A first fact should surprise us, or rather would surprise us if we were not used to it. How does it happen… — Henri Poincare Copy Share Image
Thus, be it understood, to demonstrate a theorem, it is neither necessary nor even advantageous to know what it means. The geometer… — Henri Poincare Copy Share Image
The mathematical facts worthy of being studied are those which, by their analogy with other facts, are capable of leading us to the knowledge… — Henri Poincare Copy Share Image
. . . by natural selection our mind has adapted itself to the conditions of the external world. It has adopted the geometry most… — Henri Poincare Copy Share Image
If we knew exactly the laws of nature and the situation of the universe at the initial moment, we could predict exactly the situation… — Henri Poincare Copy Share Image
Absolute space, that is to say, the mark to which it would be necessary to refer the earth to know whether it really moves,… — Henri Poincare Copy Share Image
Absolute space, that is to say, the mark to which it would be necessary to refer the earth to know whether it really moves,… — Henri Poincare Copy Share Image
A cat is witty, he has nerve, he knows how to do precisely the right thing at the right moment. — Henri Poincare Copy Share Image
In the old days when people invented a new function they had something useful in mind. — Henri Poincare Copy Share Image
Mathematics has a threefold purpose. It must provide an instrument for the study of nature. But this is not all: it has a philosophical… — Henri Poincare Copy Share Image
