the frequency and uniformity of this experience,by the cuilom and habit of thought which thatfrequency and uniformity necelfarily occahon, theInternal Senfation, and the External Caufe of thatSenfation, come in our conception to be fo flriti-ly connected, that in our ordinary and carelefsway of thinking, we are apt to conlider them asalmoft one and the fame thing , and therefore de-note them by one and the fame word. The con-fufion, however, is in this cafe more in the wordthan in the thought; for in reality we ftill retainfome notion of the diflin&ion, though we do notalways evolve it with that accuracy which a veryflight degree of attention might enable us to do.When we move our hand, for example, along thefurface of a very hot or of a very cold table, thoughwe fay that the table is hot or cold every part ofit, we never mean that, in any part of it, it feelsthe fenfations either of heat or of cold, but thatin every part of it, it poffeffes the power of ex-citing one or other of thofe fenfations in our bodies.

O

The philofophers who have taken fo much painsto prove that there is no heat in the fire, mean-ing that the fenfation or feeling of heat is not inthe fire, have labored to refute an opinion whichthe molt ignorant of mankind never entertained.But the fame word being, in common language,employed to Signify both the fenfation and thepower of exciting that fenfation, they, withoutknowing it perhaps, or intending it, have takenadvantage of this ambiguity, and have triumphedin their own Superiority, when by irrefiflible