Chapter III. continues the subject, and examines objections.  The first objection taken up is that derived from the influence of education, with which he combines the farther objection (of Locke and his followers) arising from the diversity of men’s moral judgments in various nations.  With regard to education, he contends that there are limits to its influence, and that however it may modify, it cannot create our judgments of right and wrong, any more than our notions of beauty and deformity.  As to the historical facts relating to the diversity of moral judgments, he considers it necessary to make full allowance for three circumstances—­I.—­Difference of situation with regard to climate and civilization.  II.—­Diversity of speculative opinions, arising from difference of intellectual capacity; and, III.—­The different moral import of the same action under different systems of behaviour.  On the first head he explains the indifference to theft from there being little or no fixed property; he adduces the variety of sentiments respecting Usury, as having reference, to circumstances; and alludes to the differences of men’s views as to political assassination.  On the second head he remarks, that men may agree on ends, but may take different views as to means; they may agree in recognizing obedience to the Deity, but differ in their interpretations of his will.  On the third point, as regards the different moral import of the same action, he suggests that Locke’s instance of the killing of aged parents is merely the recognized mode of filial affection; he also quotes the exceeding variety of ceremonial observances.

Chapter IV. comments farther on the objections to the reality and immutability of moral distinctions and to the universal diffusion of the moral faculty.  The reference is, in the first instance, to Locke, and then to what he terms, after Adam Smith, the licentious moralists—­La Rochefoucauld and Mandeville.  The replies to these writers contain nothing special to Stewart.

Chapter V. is the Analysis of our Moral Perceptions and Emotions.  This is a somewhat singular phrase in an author recognizing a separate inborn faculty of Right.  His analysis consists in a separation of the entire fact into three parts:—­the perception of an action as right or wrong; (2) an emotion of pleasure or pain, varying according to the moral sensibility:  (3) a perception of the merit or demerit of the agent.  The first is of course the main question; and the author gives a long review of the history of Ethical doctrines from Hobbes downwards, interspersing reflections and criticisms, all in favour of the intuitive origin of the sense.  As illustrative parallels, he adduces Personal Identity, Causation, and Equality; all which he considers to be judgments involving simple ideas, and traceable only to some primitive power of the mind.  He could as easily conceive a rational being formed to believe the three angles of a triangle to be equal to one right angle, as to believe that there would be no injustice in depriving a man of the fruits of his labours.