David Hume

Our most holy religion is founded on faith, not on reason; and 'tis a sure method of exposing it to put it to such a trial as it is by no means fitted to endure.

Every thing in the world is purchased by labour.

Custom, then, is the great guide of human life. It is that principle alone which renders our experience useful to us, and makes us expect, for the future, a similar train of events with those which have appeared in the past.

If we would satisfy ourselves, therefore, concerning the nature of that evidence, which assures us of matters of fact, we must enquire how we arrive at the knowledge of cause and effect.

There is a great difference betwixt a man, who is by nature diffident, and one, who is so by habit and reflection.

The life of man is a perpetual flux of motion. All his thoughts, sentiments, and actions are in a continual succession, and never remain for any considerable time in the same state.

There are no such things as moral demonstrations.

The most perfect philosophy of the natural kind only staves off our ignorance a little longer: as perhaps the most perfect philosophy of the moral or metaphysical kind serves only to discover more openly the vast extent of our ignorance.

All doctrines, however, are not to be admitted on the same footing. Each must be tried by its own proper evidence; and as this evidence is more or less convincing, we must assent to it more or less strongly.

The passion of love is a much more powerful principle of action than reason.

Liberty, according to the most common acceptation of the word, is an entire absence of all external impediments of motion.

The general maxims of morality are insufficient to determine us to action.

To be a philosophical sceptic is, in a man of letters, the first and most essential step towards being a true philosopher.

There is no such thing as chance in the world.

All belief of matter of fact or real existence is derived merely from some object present to the memory or senses, and a customary conjunction betwixt that and some other object.

The greater the object, the less it can be conceived by the imagination.

Whatever is may not be, and whatever is not may be.

The chief spring or actuating principle of the human mind is pleasure or pain.

No man ever threw away life, while it was worth keeping.

The passions are the only causes of action, and reason is and ought only to be the slave of the passions.