This book is typical Peter Kreeft: it couldn't be boring if it tried. The book gives ten or so arguments, for and against, moral relativism. The moral absolutist is played by a Muslim. The relativist by a liberal feminist.
Ben Isa argues that relativism is the most serious crisis to civilisation. He documents from history that all civilizations have presupposed some absolute moral code. Any civilization that operated on relativism, he argues, commits suicide.
The key arguments, that I have found most persuasive:
1) relativism has an absolutist premise in it: it argues that it is *good* to be relativist and *bad* to be absolutist. These are normative, absolutist judgments which are not consistent with the relativist claim.
2) The notion of progress demands an absolutist standard. If there is no absolute standard, and values are relative, how can a society make progress? To what is it progressing?
3) If relativism is true, then we must condemn men like Martin Luther King Jr, Ghandi, and abolitionists--people who are usually championed by relativists (I would have chosen different examples, but that's beside the point). They are known as cultural prophets, calling the evils of a society to account. But do you see the problem? If a society is the source and norm for values, and a society determines what is right and wrong (like slavery and the oppression of women), then who is the prophet to blame them? All of the cultural prophets have assumed a moral law to which society must be judged. This moral law, obviously, is absolutist.
4) Kreeft's arguments from the history of philosophy were quite impressive.
Pros: the book was extremely well-written. It was very insightful and covered the standard arguments used in the debates. Some pages were so good one had to stand and applaud.
Cons: his choice of a Muslim will no doubt bother some readers. I, personally, would have chosen a different hero. True, Islamic morals are absolute, but if consistent, they look a lot different than biblical revelation. 2) Kreeft sold the farm on evolution. He masterfully refuted it and then in the next paragraph affirmed it. I know what he is getting at but this is a poor way to phrase it.
I recommend this book.