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 SERMON II.

UPON HUMAN NATURE.

speculative truth admits of different kinds of proof, so likewise moral obligations may be shown by different methods. If the real nature of any creature leads him, and is adapted to such and such purposes only, or more than to any other; this is a reason to believe the Author of that nature intended it for those purposes. Thus there is no doubt the eye was intended for us to see with. And the more complex any constitution is, and the greater variety of parts there are which thus tend to some one end, the stronger is the proof that such end was designed. However, when the inward frame of man is considered as any guide in morals, the utmost caution must be used that none make peculiarities in their own temper, or anything which is the effect of particular customs, though observable in several, the standard of what is common to the species; and, above all, that the highest principle be not forgot or excluded, that to which belongs the adjustment and correction of all other inward movements and affections: which principle will of course have some influence, but which, being in nature supreme, as shall now be shown, ought to preside over and govern all the rest. The difficulty of rightly observing the two former cautions, the appearance there is of some small diversity amongst mankind with