But this sense must certainly acquire new force, when reflecting on itself, it approves of those principles, from whence it is derived, and finds nothing but what is great and good in its rise and origin.  Those who resolve the sense of morals into original instincts of the human mind, may defend the cause of virtue with sufficient authority; but want the advantage, which those possess, who account for that sense by an extensive sympathy with mankind.  According to their system, not only virtue must be approved of, but also the sense of virtue:  And not only that sense, but also the principles, from whence it is derived.  So that nothing is presented on any side, but what is laudable and good.

This observation may be extended to justice, and the other virtues of that kind.  Though justice be artificial, the sense of its morality is natural.  It is the combination of men, in a system of conduct, which renders any act of justice beneficial to society.  But when once it has that tendency, we naturally approve of it; and if we did not so, it is impossible any combination or convention coued ever produce that sentiment.

Most of the inventions of men are subject to change.  They depend upon humour and caprice.  They have a vogue for a time, and then sink into oblivion.  It may, perhaps, be apprehended, that if justice were allowed to be a human invention, it must be placed on the same footing.  But the cases are widely different.  The interest, on which justice is founded, is the greatest imaginable, and extends to all times and places.  It cannot possibly be served by any other invention.  It is obvious, and discovers itself on the very first formation of society.  All these causes render the rules of justice stedfast and immutable; at least, as immutable as human nature.  And if they were founded on original instincts, coued they have any greater stability?

The same system may help us to form a just notion of the happiness, as well as of the dignity of virtue, and may interest every principle of our nature in the embracing and cherishing that noble quality.  Who indeed does not feel an accession of alacrity in his pursuits of knowledge and ability of every kind, when he considers, that besides the advantage, which immediately result from these acquisitions, they also give him a new lustre in the eyes of mankind, and are universally attended with esteem and approbation?  And who can think any advantages of fortune a sufficient compensation for the least breach of the social virtues, when he considers, that not only his character with regard to others, but also his peace and inward satisfaction entirely depend upon his strict observance of them; and that a mind will never be able to bear its own survey, that has been wanting in its part to mankind and society?  But I forbear insisting on this subject.  Such reflections require a work a-part, very different from the genius of the present.  The anatomist ought never to emulate the painter;