This deduction of morals from self-love, or a regard to private interest, is an obvious thought, and has not arisen wholly from the wanton sallies and sportive assaults of the sceptics. To mention no others, Polybius, one of the gravest and most judicious, as well as most moral writers of antiquity, has assigned this selfish origin to all our sentiments of virtue. [Footnote: Undutifulness to parents is disapproved of by mankind, [Greek quotation inserted here]. Ingratitude for a like reason (though he seems there to mix a more generous regard) [Greek quotation inserted here] Lib. vi cap. 4. (Ed. Gronorius.) Perhaps the historian only meant, that our sympathy and humanity was more enlivened, by our considering the similarity of our case with that of the person suffering; which is a just sentiment.] But though the solid practical sense of that author, and his aversion to all vain subtilties, render his authority on the present subject very considerable; yet is not this an affair to be decided by authority, and the voice of nature and experience seems plainly to oppose the selfish theory. We frequently bestow praise on virtuous actions, performed in very distant ages and remote countries; where the utmost subtilty of imagination would not discover any appearance of self-interest, or find any connexion of our present happiness and security with events so widely separated from us. A generous, a brave, a noble deed, performed by an adversary, commands our approbation; while in its consequences it may be acknowledged prejudicial to our particular interest. Where private advantage concurs with general affection for virtue, we readily perceive and avow the mixture of these distinct sentiments, which have a very different feeling and influence on the mind. We praise, perhaps, with more alacrity, where the generous humane action contributes to our particular interest: But the topics of praise, which we insist on, are very wide of this circumstance. And we may attempt to bring over others to our sentiments, without endeavouring to convince them, that they reap any advantage from the actions which we recommend to their approbation and applause.