[W]e should say: 'Causes almost identical take almost the same time to produce almost the same effects.' - Henri Poincaré

Mathematicians do not study objects, but relations between objects. Thus, they are free to replace some objects by others so long as the relations remain unchanged. Content to them is irrelevant: they are interested in form only...

Les hommes ne s’entendent pas, parce qu’ils ne parlent pas la même langue et qu’il y a des langues qui ne s’apprennent pas.
[Men do not get along because they do not speak the same language and there are languages ​​that cannot be learned.]

Scientists believe there is a hierarchy of facts and that among them may be made a judicious choice. They are right, since otherwise there would be no science...