These opposite sensations are related to the opposite passions.

The beauty or deformity is closely related to self, the object of both these passions.

No wonder, then our own beauty becomes an object of pride, and deformity of humility.
But this effect of personal and bodily qualities is not only a proof of.
the present system, by shewing that the passions arise not in this case without all the circumstances I have required, but may be employed as a stronger and more convincing argument.

If we consider all the hypotheses, which have been formed either by philosophy or common reason, to explain the difference betwixt beauty and deformity, we shall find that all of them resolve into this, that beauty is such an order and construction of parts, as either by the primary constitution of our nature, by custom, or by caprice, is fitted to give a pleasure and satisfaction to the soul.

This is the distinguishing character of beauty, and forms all the difference betwixt it and deformity, whose natural tendency is to produce uneasiness.