In his twelve-lecture series, Ross explores several debates regarding the core issues in moral theory. Moral life, he observes, has been regarded as either obedience to laws or as a striving after goods. Moral theories have been further subdivided into reaction and causal theories regarding the meaning of ethical terms. The third distinction he examines separates moral theories into the naturalistic and non-naturalistic. The notion of right is given primacy over the good in the order of discussion, and examined in light of various accounts of it. The nature of obligation is examined in relation to the concept of right, and the accounts of the rightness of an action are raised following from this. Questions of knowledge and motive arise in relation to what the concept of right is. Indeterminacy and determinism are assessed as to their bearing on moral philosophy, forming an interlude before the nature of goodness is examined. A notion of ‘goodness’ is essential in the study of ethics, and Ross explores its nature as a predicate, its meaning and the sort of property it is. The final lecture builds upon this to present an account of moral goodness: the types of things that constitute the class of the morally good. Though goodness and rightness are independent, a completely good act must be a right act.