For a solitary animal egoism is a virtue that tends to preserve and improve the species: in any kind of community it becomes a destructive vice.

An animal that embarks on forming states without greatly restricting egoism will perish.

Every vice was once a virtue, and may become respectable again, just as hatred becomes respectable in wartime

Virtue practiced to be seen is not real virtue; vice which fears to be seen is real vice

The verbal interpretation, on the other hand, i.e. the metaphysics of quantum physics, is on far less solid ground. In fact, in more than forty years physicists have not been able to provide a clear metaphysical model.

The scientist only imposes two things, namely truth and sincerity, imposes them upon himself and upon other scientists.