All that belongs to human understanding, in this deep ignorance and obscurity, is to be sceptical, or at least cautious, and not to admit of any hypothesis whatever, much less of any which is supported by no appearance of probability.

Obscurity, indeed, is painful to the mind as well as to the eye; but to bring light from obscurity, by whatever labour, must needsbe delightful and rejoicing.

The feelings of our heart, the agitation of our passions, the vehemence of our affections, dissipate all its conclusions, and reduce the profound philosopher to a mere plebeian

And what is the greatest number? Number one.

It is still open for me, as well as you, to regulate my behavior, by my experience of past events.

Apart from the representational content of an idea there is another component: its force and vivacity, its impetus.

Friendship is a calm and sedate affection, conducted by reason and cemented by habit; springing from long acquaintance and mutual obligations, without jealousies or fears, and without those feverish fits of heat and cold, which cause such an agreeable torment in the amorous passion.