This would be accusing the Author of our existence, and converting his noblest gifts into poison. It may appear surprising to some, that we should have stopt here to investigate and explain the truth of a principle, which one would imagine is obvious to every body, to the learned as well as the vulgar. But a great many, after acknowledging this principle, seem to lose sight of it, and, not attending to the consequences, that flow from it, erect their systems on different, and sometimes quite opposite foundations. But if it be true, that man does nothing but with a view of happiness, it is no less certain, that reason is the only way he has to attain it. In order to establish this second proposition or truth, we have only to attend to the very idea of happiness, and to the notion we have of good and evil.
Evil is the opposite of good.
It is only therefore by investigating the nature of things, as also the relations, they have between themselves and with us, that we are capable of discovering their fitness or disagreement with our felicity, of discerning good from evil, of ranging every thing in its proper order, of setting a right value on each, and of regulating consequently our researches and desires. Now it is reason alone, that directs all these operations. Reason is therefore the only mean, in every respect, that man has left to attain to happiness, and the principal end, for which he has received it. Thus we are conducted naturally to the first idea of the word Right , which in its most general sense, and that, to which all the particular significations bear some relation, is nothing else but whatever reason certainly acknowledges, as a sure and concise mean of attaining happiness, and approves as such. This definition is the result of the principles hitherto established.