The affections are not susceptible of any impression from the refinements of reason or imagination; and it is always found that a vigorous exertion of the latter faculties, necessarily, from the narrow capacity of the human mind, destroys all activity in the former.

Our predominant motive or intention is, indeed, frequently concealed from ourselves when it is mingled and confounded with other motives which the mind, from vanity or self-conceit, is desirous of supposing more prevalent: but there is no instance that a concealment of this nature has ever arisen from the abstruseness and intricacy of the motive.

A man that has lost a friend and patron may flatter himself that all his grief arises from generous sentiments, without any mixture of narrow or interested considerations: but a man that grieves for a valuable friend, who needed his patronage and protection; how can we suppose, that his passionate tenderness arises from some metaphysical regards to a self-interest, which has no foundation or reality?
We may as well imagine that minute wheels and springs, like those of a watch, give motion to a loaded waggon, as account for the origin of passion from such abstruse reflections.
Animals are found susceptible of kindness, both to their own species and to ours; nor is there, in this case, the least suspicion of disguise or artifice.

Shall we account for all THEIR sentiments, too, from refined deductions of self-interest?
Or if we admit a disinterested benevolence in the inferior species, by what rule of analogy can we refuse it in the superior?
Love between the sexes begets a complacency and good-will, very distinct from the gratification of an appetite.

Tenderness to their offspring, in all sensible beings, is commonly able alone to counter-balance the strongest motives of self-love, and has no manner of dependance on that affection.