« Celui qui peut, agit. Celui qui ne peut pas, enseigne. »
George Bernard Shaw – Maximes pour révolutionnaires (1903)
« He who can, does. He who cannot, teaches.
A learned man is an idler who kills time with study. Beware of his false knowledge: it is more dangerous than ignorance.
Activity is the only road to knowledge.
No man can be a pure specialist without being in the strict sense an idiot. »