No man is absolutely indifferent to the happiness and misery of others.

The first has a natural tendency to give pleasure; the second, pain.

This every one may find in himself.

It is not probable, that these principles can be resolved into principles more simple and universal, whatever attempts may have been made to that purpose.

But if it were possible, it belongs not to the present subject; and we may here safely consider these principles as original; happy, if we can render all the consequences sufficiently plain and perspicuous!] Have we any difficulty to comprehend the force of humanity and benevolence?
Or to conceive, that the very aspect of happiness, joy, prosperity, gives pleasure; that of pain, suffering, sorrow, communicates uneasiness?
The human countenance, says Horace ['Uti ridentibus arrident, ita flentibus adflent Humani vultus,'-- Hor.], borrows smiles or tears from the human countenance.