XII OF THE PRIDE AND HUMILITY OF ANIMALS Thus in whatever light we consider this subject, we may still observe, that die causes of pride and humility correspond exactly to our hypothesis, and that nothing can excite either of these passions, unless it be both related to ourselves, and produces a pleasure or pain independent of the passion.

We have not only proved, that a tendency to produce pleasure or pain is common to all the causes of pride or humility, but also that it is the only thing, which is common; and consequently is the quality, by which they operate.

We have farther proved, that the most considerable causes of these passions are really nothing but the power of producing either agreeable or uneasy sensations; and therefore that all their effects, and amongst the rest, pride and humility, are derived solely from that origin.

Such simple and natural principles, founded on such solid proofs, cannot fail to be received by philosophers, unless opposed by some objections, that have escaped me.
It is usual with anatomists to join their observations and experiments on human bodies to those on beasts, and from the agreement of these experiments to derive an additional argument for any particular hypothesis.

It is indeed certain, that where the structure of parts in brutes is the same as in men, and the operation of these parts also the same, the causes of that operation cannot be different, and that whatever we discover to be true of the one species, may be concluded without hesitation to be certain of the other.