Chapter I. considers the causes of this influence of Fortune.  Gratitude requires, in the first instance, that some pleasure should have been conferred; Resentment pre-supposes pain.  These passions require farther that the object of them should itself be susceptible of pleasure and pain; they should be human beings or animals.  Thirdly, It is requisite that they should have produced the effects from a design to do so.  Now, the absence of the pleasurable consequences intended by a beneficent agent leaves out one of the exciting causes of gratitude, although including another; the absence of the painful consequences of a maleficent act leaves out one of the exciting causes of resentment; hence less gratitude seems due in the one, and less resentment in the other.

Chapter II. treats of the extent of this influence of Fortune.  The effects of it are, first, to diminish, in our eyes, the merit of laudable, and the demerit of blameable, actions, when they fail of their intended effects; and, secondly, to increase the feelings of merit and of demerit beyond what is due to the motives, when the actions chance to be followed by extraordinary pleasure or pain.  Success enhances our estimate of all great enterprises; failure takes off the edge of our resentment of great crimes.

The author thinks (Chapter III.) that final causes can be assigned for this irregularity of Sentiments.  In the first place, it would be highly dangerous to seek out and to resent mere bad intentions.  In the next place, it is desirable that beneficent wishes should be put to the proof by results.  And, lastly, as regards the tendency to resent evil, although unintended, it is good to a certain extent that men should be taught intense circumspection on the point of infringing one another’s happiness.

PART III. is entitled OF THE FOUNDATION OF OUR JUDGMENTS CONCERNING OUR OWN SENTIMENTS AND CONDUCT, AND OF THE SENSE OF DUTY.

Chapter I. is ’Of the Principle of Self-approbation and of Self-disapprobation.’  Having previously assigned the origin of our judgments respecting others, the author now proceeds to trace out our judgments respecting ourselves.  The explanation is still the same.  We approve or disapprove of our own conduct, according as we feel that the impartial spectator would approve or disapprove of it.

To a solitary human being, moral judgments would never exist.  A man would no more think of the merit and demerit of his sentiments than of the beauty or deformity of his own face.  Such criticism is exercised first upon other beings; but the critic cannot help seeing that he in his turn is criticised, and he is thereby led to apply the common standard to his own actions; to divide himself as it were into two persons—­the examiner or judge, and person examined into, or judged of.  He knows what conduct of his will be approved of by others, and what condemned, according to the standard he himself employs upon others; his concurrence in this approbation or disapprobation is self-approbation or self-disapprobation.  The happy consciousness of virtue is the consciousness of the favourable regards of other men.