He may well have had it entirely right on the idea that "what should be" is nonsense in light of "what is". This view has been espoused by a variety of contemporary philosophers: G Moore's famous adadge "one cannot derive an ought from an is", for example; Bertrand Russel's view of the universe as brute fact; Wittgenstein's "whereof one cannot speak, thereof one must be silent".
I must admit, I really find it hard to come to any logically consistent argument for the existence of any objective moral framework (that is, any "should"s, "ought"s, "good"s, "evil"s, etc., etc). I'd be interested to know if anyone thinks they can.
I am a strong fan of reducibility and think that very complex questions such as the Good, True and Beautiful and be reduced to the foundations and discovered as implicit or having to be deduced.
When I think of the Good I am often tempted to say that there must be an implicit Good, the trickle down effect of Goodness. In this theory there must be an entity or agent of complete Good so that we (as imperfect beings) can strive to achieve. This makes it so easy for people to assume there must be a "god" or other ultimate entity. I think that just like when Newton gave up on balancing his equations for the stability of the solar system and said it must be god, saying that there must be a god for morality to exist is nothing more than a lack of imagination.
Unfortunatly as a man of evidence I must ask myself what kind of proof is there for a standard of Goodness. The problem with religion is that all of its claims can only be validated after death and therefore serve no purpose in this debate. There seems so far in history to be no eternal judge that lives in our 4 dimentional world passing rulings on human actions as either Good or Not Good. Good people die horrible deaths and Bad people do too, while some of the most beautiful human achievments are taking place (journey to the moon) a threat of Mutually Assured Destruction hangs on the minds of the world. I believe this means we are left with looking inwards at what makes us human and what is good for us.
We all know that Darwinian natural selection works for the benifit of the individual and its offspring. There is no Darwinian sense of group survival or even human kind survival, only of the individual and its genes. We also speculate that verying levels of altruism we all experience: Kinship altruism (survival of the gene) and Reciprical Altruism (game theory), are present due to their tendency for survival in their respective gene machines (life). We have also seen work in neuroscience reveal the presence of a mirror neuron that may be a genetically dominant feature in humans to feel physically affected when witnessing pain and suffering in others.
With these biological accounts for altruism and by extention morality (preventing personal suffering for survival as well as the survival of others) by definition we can say humans are by nature social and moral. However, this means that morality only indicates fitness to survive in the grand scheme of evolution. Moral acts may specifically lead to a persons death (martyrdom) though the benifits to the human variants with this sense of altruism tended to survive better.
So, is morality nothing more than an elaborate survival mechanism relying on emotion rather than reason to direct survivability? I think that there is one more piece of the puzzle that confuses the whole issue. Human consciousness, more specifically high reason is the variable that changed the realities of human evolution. With this high level reasoning we were able to go beyond what tends to cause survival for the reproducing agents the species and start making rules to do that for us. Instead of allowing nature to take its course we build up institutions and other frameworks of control to make not only a survivable society but one that avoids suffering.
Instead of mere life (natural selection driven evolution) we now have life, one where we avoid suffering and seek pleasure. I believe in the search for an independant and eternal order of the Good beyond the harsh realities of pure survival we have made assumptions that have served as an actual detriment to human happiness. One example would be the outlook on homosexuality and bisexuality. With an objective view this practice offers absolutely no undue risk on survivability (ofcorse beyond the structure of societal hate) though by many is considered a moral evil. For those who are born gay or bisexual or even those who choose it (if that is infact possible) the life of having romantic relationships with other same sexed individuals leads to happiness and a more personally fulfilled life (again, beyond the social constraints).
To conclude, I believe that this question comes down to a long and short answer. On one hand, there is an eternal morality however it is pure survivability, mere life. Human consciousness (once it came along) attempted to find something more than mere life. Sometimes it erred (homosexuality) however most of the time it has understood happiness. The golden rule isn't in existence because it follows a moral precept, it is because it leads to greater happiness for all parties involved (with occasional exceptions.) So, basicly I think that humans are predisposed to pure survival, mere life, and that sometimes altruism loses out to pure survival mechanisms (lying, cheating, etc) however human consciousness along with the altruistic dispositions can form what we commonly understand as "morality."