T 2.1.12.6

The next question is, whether, since those passions are the same, and arise from the same causes thro' the whole creation, the manner, in which the causes operate, be also the same. According to all rules of analogy, this is justly to be expected; and if we find upon trial, that the explication of these phænomena, which we make use of in one species, will not apply to the rest, we may presume that that explication, however specious, is in reality without foundation.