Mathematics allows for no hypocrisy and no vagueness.

Love born in the brain is more spirited, doubtless, than true love, but it has only flashes of enthusiasm; it knows itself too well, it criticizes itself incessantly; so far from banishing thought, it is itself reared only upon a structure of thought.

A woman of generous character will sacrifice her life a thousand times over for her lover, but will break with him for ever over a question of pride.

The first characteristic of Rossini's music is speed - a speed which removes from the soul all the sombre emotions that are so powerfully evoked within us by the slow strains in Mozart. I find also in Rossini a cool freshness, which, measure by measure, makes us smile with delight.

The Russians imitate French ways, but always at a distance of fifty years.

Logic is neither an art nor a science but a dodge.

Jean Jacques Rousseauis nothing but a fool in my eyes when he takes it upon himself to criticise society; he did not understand it, and approached it with the heart of an upstart flunkey.... For all his preaching a Republic and the overthrow of monarchical titles, the upstart is mad with joy if a Duke alters the course of his after-dinner stroll to accompany one of his friends.