David Hume

“ Thus in whatever light we consider this subject, we may still observe, that the 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 prov'd, that a tendency to produce pleasure or pain is common to all the causes of pride or humility, but also that 'tis the only thing, which is common ”

“ There are also instances of the relation of impressions, sufficient to convince us, that there is an union of certain affections with each other in the inferior species of creatures as well as in the superior, and that their minds are frequently convey'd thro' a series of connected emotions. A dog, when elevated with joy, runs naturally into love and kindness, whether of his master or of the sex. ”

“ Thus tho' the mixture of humours and the composition of minute parts may justly be presum'd to be somewhat different in men from what it is in mere animals; and therefore any experiment we make upon the one concerning the effects of medicines will not always apply to the other ”

“ In order to decide this question, let us consider, that there is evidently the same relation of ideas, and deriv'd from the same causes, in the minds of animals as in those of men. A dog, that has hid a bone, often forgets the place ”

“ In like manner, when he has been heartily beat in any place, he will tremble on his approach to it, even tho' he discover no signs of any present danger. The effects of resemblance are not so remarkable ”