From causes which appear similar, we expect similar effects. This is the sum total of all our experimental conclusions.

When we reflect on our past sentiments and affections, our thought is a faithful mirror, and copies its objects truly; but the colours which it employs are faint and dull, in comparison of those in which our original perceptions were clothed.

For the purposes of life and conduct, and society, a little good sense is surely better than all this genius, and a little good humour than this extreme sensibility.

Such is the nature of novelty that where anything pleases it becomes doubly agreeable if new; but if it displeases, it is doubly displeasing on that very account.

If ... the past may be no Rule for the future, all Experience becomes useless and can give rise to no Inferences or Conclusions.

No advantages in this world are pure and unmixed.

To consider the matter aright, reason is nothing but a wonderful and unintelligible instinct in our souls, which carries us along a certain train of ideas, and endows them with particular qualities, according to their particular situations and relations. This instinct, 'tis true, arises from past observation and experience; but can anyone give the ultimate reason, why past experience and observation produces such an effect, any more than why nature alone should produce it?