T 2.3.3.8

'Tis natural for one, that does not examine objects with a strict philosophic eye, to imagine, that those actions of the mind are entirely the same, which produce not a different sensation, and are not immediately distinguishable to the feeling and perception. Reason, for instance, exerts itself without producing any sensible emotion; and except in the more sublime disquisitions of philosophy, or in the frivolous subtilties of the schools, scarce ever conveys any pleasure or uneasiness. Hence it proceeds, that every action of the mind, which operates with the same calmness and tranquillity, is confounded with reason by all those, who judge of things from the first view and appearance. Now 'tis certain, there are certain calm desires and tendencies, which, tho' they be real passions, produce little emotion in the mind, and are more known by their effects than by the immediate feeling or sensation. These desires are of two kinds; either certain instincts originally implanted in our natures, such as benevolence and resentment, the love of life, and kindness to children; or the general appetite to good, and aversion to evil, consider'd merely as such. When any of these passions are calm, and cause no disorder in the soul, they are very readily taken for the determinations of reason, and are suppos'd to proceed from the same faculty, with that, which judges of truth and falshood. Their nature and principles have been suppos'd the same, because their sensations are not evidently different.