Thanks, a great read! Still the fact that so many brilliant thinkers can not agree on the definite answers to the ethical questions seems to me to be not the evidence that they are all climbing for the same summit from different sides (like it was for Parfit) but rather the evidence that the questions themselves are misstated.
This proposition accounts for about half of the history of western philosophy. The other half unsurprisingly concerns itself with the relationship between humans and '[g|G]od[s]?'. Vide Wittgenstein for a modern(ish) view of both.
> so many brilliant thinkers can not agree on the definite answers to the ethical questions
They can, and do. The really big (academic/philosophical) problem isn't ethical, it's meta-ethical: they agree that, e.g., murder, rape, discrimination and fraud are wrong, but the arguments they find sufficiently sound to undergird those conclusions are mutually exclusive. More worryingly, the premises and inferential rules these arguments rest on undermine each other: Murder is bad because if you generalized the actions of murderers, no humans would be left; Wrong, murder is bad because the Right to Life is given by a Natural Law; Wrong, murder is bad because it is moral to maximize happiness/fulfilment over a population and the dead form a local minimum; etc, etc...
Some of this stuff seriously reads like an OO-evangelist trying to convince a lisp-er of the benefits of encapsulation. The OO'er says "separate concerns to manage state" and the lisp-er replies "immutability", and neither realizes that actually, they're operating in different domains, because enough vocabulary is shared by them that they can each rationally argue that "that other guy is nuts". Their arguments are incommensurable, but neither one is outrageously wrong.
That's kind of what modern meta-ethics is like, except with about 2,000 extra years of potential divergence, and a few dozen Turings, Knuths and Dijkstras on each different side of the debate.
Yes, everybody kind of agrees on what are the right answers in common situations (like "murder of a human who does not present a threat to others is bad") but for every principle which aspires to be general its detractors have been able to present an example where it leads to conclusions which can not be universally accepted as ethical. For me that is strong evidence that there is no such principle.
An apt analogy with software engineering! I guess I believe that there are no universal principles there either. If the OO-evangelist and the lisper then each go on to develop useful and robust applications then they are both right (and that puts me squarely into consequentialist bucket with regards to software :)).
