T 2.1.12.9

Thus all the internal principles, that are necessary in us |to produce either pride or humility, are common to all creatures; and since the causes, which excite these passions, are likewise the same, we may justly conclude, that these causes operate after the same manner thro' the whole animal creation. My hypothesis is so simple, and supposes so little reflection and judgment, that 'tis applicable to every sensible creature; which must not only be allow'd to be a convincing proof of its veracity, but, I am confident, will be found an objection to every other system.