How is it that there are so many minds that are incapable of understanding mathematics? ... the skeleton of our understanding, ... and actually they … - Henri Poincaré

In reality, space is therefore amorphous, a flaccid form, without rigidity, which is adaptable to everything, it has no properties of its own. To geometrize is to study the properties of our instruments, that is, of solid bodies.

Behold... the only... [rule] we can follow: when a phenomenon appears... as the cause of another, we regard it as anterior. ...[T]herefore by cause... we define time; but...how do we recognize which is the cause and which the effect? We assume... the anterior fact, the antecedent, is the cause of the... consequent. It is then by time that we define cause. ...[S]hall we escape from this vicious circle?

La recherche de la vérité doit être le but de notre activité ; c'est la seule fin qui soit digne d'elle. Sans doute nous devons d'abord nous efforcer de soulager les souffrances humaines, mais pourquoi ?