The greatest trouble in the world is that fools are very sure of themselves, while the wise are full of doubts.
— (Switzerland) Russel
It can be affirmed that both mind and body, if indulged with excessive ease, will be infected with illness like a plague.
— (UK) Dickens, "Barnaby Rudge"
Life is prolonged in the development of thought, for thought is the measure of life.
— Leland, "The Gods Return"