This rule we find still to hold good [Seventh and Eighth Experiments.] even under the appearance of its contrary; and as relation is frequently experienced to have no effect; which upon examination is found to proceed from some particular circumstance, that prevents the transition; so even in instances, where that circumstance, though present, prevents not the transition, it is found to arise from some other circumstance, which counter-balances it.

Thus not only the variations resolve themselves into the general principle, but even the variations of these variations.
SECT.

III DIFFICULTIES SOLVED After so many and such undeniable proofs drawn from daily experience and observation, it may seem superfluous to enter into a particular examination of all the causes of love and hatred.

I shall, therefore, employ the sequel of this part, First, In removing some difficulties, concerning particular causes of these passions.

Secondly, In examining the compound affections, which arise from the mixture of love and hatred with other emotions.
Nothing is more evident, than that any person acquires our kindness, or is exposed to our ill-will, in proportion to the pleasure or uneasiness we receive from him, and that the passions keep pace exactly with the sensations in all their changes and variations.