Perhaps you regard this thinking about myself as a waste of time - but how can I be a logician before I'm a human being! Far the most important thing… - Ludwig Wittgenstein

If we hear a Chinese we tend to take his speech for inarticulate gurgling. Someone who understands Chinese will recognize language in what he hears. Similarly I often cannot recognize the human being in someone etc.

A certeza é por assim dizer um tom de voz em que alguém declara como são as coisas, mas não se infere desse tom que tem razão.

Brouwer is right when he says that the properties of his Pendelzahl [pendulum number] are incompatible with the law of the excluded middle. But, saying this doesn’t reveal a peculiarity of propositions about infinite aggregates. Rather, it is based on the fact that logic presupposes that it cannot be a priori — i.e. logically — impossible to tell whether a proposition is true or false. For, if the question of the truth or falsity of a proposition is a priori undecidable, the consequence is that the proposition loses its sense, and the consequence of this is precisely that the propositions of logic lose their validity for it.