From daily experience of the fact that we judge the conduct of others, and they ours, and from the wish to gain their approval, arises the habit of subjecting our own actions to criticism. We learn to look at ourselves through the eyes of others, we assign the spectator and judge a place in our own heart, we make his calm objective judgment our own, and hear the man within calling to us: Thou art responsible for thy acts and intentions. In this way we are placed in a position to overcome two great delusions, one of passion, which overestimates the present at the expense of the future, and one of self-love, which overestimates the individual at the expense of other men; delusions from which the impartial spectator is free, for the pleasure of the moment seems to him no more desirable than pleasure to come, and one person is just the same to him as another. Through comparison of like cases in the exercise of self-examination certain rules or principles are formed concerning what is right and good. Reverence for these general rules of living is called the sense of duty. The last step in the process consists in our enhancement of the binding authority of moral rules by looking on them as commands of God. Here Smith adds subtle discussions of the question, in what cases actions ought to be done simply out of regard for these abstract maxims, and in what others we welcome the co-operation of a natural impulse or passion. We ought to be angry and to punish with reluctance, merely because reason enjoins it, but, on the other hand, we should be benevolent and grateful from affection; she is not a model wife who performs her duties merely from a sense of duty, and not from inclination also. Further, in all cases where the rules cannot be formulated with perfect exactness and definiteness (as they can in the case of justice), and are not absolutely valid without exception, reverence for them must be assisted by a natural taste for modifying and supplementing the general maxims to suit particular instances.