If you can, check out this article in New Scientist (26 Nov 2005)
I was not impressed, so I wrote them this letter (which I doubt they'll print so I might as well expose it to the public gaze here):
Most attempts at seeking moral absolutes are confused and I'm afraid Dan Jones effort (26 November) was no better than most.
Consider, for example, his opening scenario. The trolley train is coming and "all you've got is a hefty guy standing in front of you. If you push him onto the line, his bulk will be enough to stop the runaway train". First, even within its own terms that is an incorrectly posed option. If "I" am present and capable of pushing the hefty guy onto the line, there is obviously another option and one which is far more "moral". I can sacrifice myself.
The basis for all philosophical errors concerning morality is - as Bertrand Russell pointed out in his "History of Western Philosophy" - that ALL attempts at defining "the good" are based on the flawed assumption that life itself is "good". It is, however, just as credible that "Life" is more correctly defined as an unwanted organic pollutant with no more ethical value than the mould on your bathroom ceiling.
That living things exhibit the tendency and apparent desire to continue living is a necessary biological program without which dna would fail. But we have no basis for concluding that dna is "right" to program us this way.
Later he poses the non (moral) problem of incest. First, the revulsion is not innate. This is obvious if the brother and sister were separated at birth and have never met. They are as likely to be sexually attracted to each other as any other random pair. The "revulsion" is entirely psycho-cultural but, nevertheless, based on a sound genetic judgement not just an abstract notion of right and wrong.
Elsewhere we have references to things like "the wisdom of repugnance" - which is, of course, the basis of racism, homophobia and various other extremely UNwise moral positions.
Finally we have the obligatory meaningless questionnaires. Any half competent philosopher - however idealistic - has to "completely disagree" with every question in the Idealism section because they are poorly worded. Take just the first question for instance: "It is NEVER necessary to sacrifice the welfare of others" (emphasis added). Only a fool or someone who routinely takes questions at surface value only could agree. Anyone who did agree would, logically, have to stop eating for a start (the welfare of everything you eat is somewhat impaired by the process). Obviously the author means "other people" rather than just "others" but that itself is a huge moral leap. And equally obviously he probably didn't mean to include the word "never" which renders the question absolute and leaves no room for negotiation.
Similarly, on the "Relativism" questionnaire, the first question ("What is ethical varies...") is presumably (as the Title suggests) designed to separate out those who consider ethics to be absolute from those who consider it to be relative. But anyone who considers ethics to be absolute has to "completely disagree" with all questions. There can be no grey areas for such people - so the question is binary (yes or no) rather than continuous (1-9). In any case, even a relativist will have some difficulty with the question because, again, it is posed in precisely the kind of absolute terms a relativist should reject. A relativist would want to see the word "considered" inserted thus: "What is considered ethical varies...". But even so, it is not any kind of moral question itself. It is a purely empirical observation along the lines of an opinion poll. Perception of ethics DOES vary from one society to another.
This leads to my final point which is that the only philosophically consistent basis for a value free ethical code is the observation that all living things behave as though they want to go on living. We do not need to define this as "good" we can simply acknowledge it as empirical data. Moving on from there, however, we can (not, please note, "should") choose to make this the basis of our social decision making. In other words we can collectively decide that the course most likely to provide the greatest degree of survival is the course we will endorse and collaborate to achieve.
However, what constitutes "the greatest degree of survival" is partly objective (effect on life expectancy etc) and partly subjective ("quality of life" etc). The subjective element means that the only way we can measure the likely outcome on survival is by measuring the feelings and opinions (which brings together the rational analysis and emotions) of all those who believe they will be affected by the decision. This is the most fundamental basis for democracy. I have begun to explore the shape of such an ethical code in my essay on how Survival Based Ethics deals with "The Ten Commandments".