NOTE: Although this book is not marketed as a "religious" book, the author adopts a conservative Christian approach to the definition of morality after running through basic philosophy. I'm giving it two stars for the author's clarity in explaining his thoughts and overview of several schools of thought, but nothing more because of the author's bias and focus on sex. I do not find it unreasonable that a philosopher's work would reflect his faith - but it seems excessive to make explicit references to that faith in a book that is not expressly marketed as a religious reference guide (see the quote below for an example of what I mean). Similarly, I'm not disputing that abortion and pre-martial sex are relevant moral issues - but a book on "everyday moral decisions" shouldn't focus on both topics to the exclusion of other topics.
[Summary by excerpt]
Non-moral choices are often “personal” in this sense: relative to the individual person or the group rather than absolute; subjective rather than objective; individual rather than universal. But moral choices are not like that, as I shall try to prove in the next chapter. Moral choices are choices between what is really, objectively right and what is really, objectively wrong. That’s why we feel guilty when we make wrong moral choices, but not when we make wrong non-moral choices. We may feel shame when we find out that we should have bought a cheaper TV or should have taken a different physical road, a short cut; but shame is not guilt.
Thomas Aquinas has a good answer to these questions. He says that there are three parts to morality, and all three parts must be good for any act to be morally good. The three are (1) the objective act itself, (2) the subjective motive, and (3) the situation, or circumstances.
You can no more be good without God than you can see without light. But you needn’t notice the light when you see objects.
"Christian sexual morality, like the rest of Christian morality, is based on human nature, on the kind of thing we are and the kind of thing sex is. It is not the changeable rules of a game we designed, but the unchangeable rules of the operating manual written by the Designer of our human nature."
Feelings and fashions are relative to each other. They are two aspects of the same worldly order. They are like money and power: each can buy the other. Fashions are the social form taken by the feelings of the fashion-makers, and feelings are the psychological form taken by social fashions. For example, most men today feel attracted to thin women because that is the fashion in our society (it was not so in the Renaissance); and that is the fashion in our society because that is how fashion-makers feel. The choice, then, is not between going by your internal feelings or by external fashions. Feelings may seem individual, even nonconformist, but they are conditioned by social fashions. The only real choice comes when you rise from the level of feelings and fashions to the level of free will and moral values. Only a choice between right and wrong is your choice; a choice between a big car and a small car in response to advertisements is really society’s choice. Many societies in history have consistently preached and inconsistently practiced the virtue of self-control, self-denial, self-discipline, both in the area of sex and in general. Why has our society pretty much abandoned not only the practice but even the preaching of this virtue? It is the mind that directs preaching, therefore the answer to that question has to be found in the realm of the mind, not the body.