The gloomy and the resentful are always found among those who have nothing to do or who do nothing.

Few moments are more pleasing than those in which the mind is concerting measures for a new undertaking.

Inquiries into the heart are not for man.

The mathematicians are well acquainted with the difference between pure science, which has only to do with ideas, and the application of its laws to the use of life, in which they are constrained to submit to the imperfections of matter and the influence of accidents.

This world, where much is to be done and little to be known.

Though the discoveries or acquisitions of man are not always adequate to the expectations of his pride, they are at least sufficient to animate his industry.

Of those that spin out trifles and die without a memorial, many flatter themselves with high opinions of their own importance, and imagine that they are every day adding some improvement to human life.