Why Aristotle is still relevant.
Aristotle is verbose and inconclusive, and sometimes plain silly. Aristotle's physics is mostly a large collection of excuses and rationalizations for evading quantitative methods and refusing to do arithmetic.
Aristotle's ethics is not particularly libertarian, and does not clearly express any particular view.
Aristotle was not very enthusiastic about liberty, and John Stuart Mills was very enthusiastic about liberty.
But for all that:
Mills's erroneous ideas were and are damaging to liberty, and Aristotle's ideas were a major reason why Europe became more free than most of humanity
Aristotle, or rather the ideas of the best of the Greeks which he expressed and summarized, are still the basic methods by which we understand ourselves and the world. This way of thinking led to both to nuclear power and to the principles expressed in the American Declaration of Independence
Everyone is in favor of liberty. The important thing is to understand how free people can live together peaceably.
What makes Aristotle important is that he was the most influential advocate of the view that one should be good for ones own sake, not for the sake of anyone else, that virtue is a particular form of selfishness.
With this view of virtue, with any view that treats virtue as a category rather than a command, then obviously there is no big deal about deducing moral truths from empirical facts. One may disagree about the facts and disagree about the conclusions, but such disagreement is the result of fallibility and imperfect knowledge, not because the task is fundamentally impossible in general. It may be impossible in some cases, difficult in many cases, but there is no fundamental unbridgeable barrier.
And if it is possible to know right from wrong, then we are not dependent upon some superior power to resolve conflicts between the desires of one person and the desires of another, so good people can themselves arrange to live in peace together.
We can resolve conflicts of interest by reference to what is right. We do not need a political apparatus with the power to make any decision on any matter in order to avoid killing each other.
Of course one cannot deduce pure altruism from facts. Then so much the worse for pure altruism!
If someone was to sacrifice a brother or a friend for "the greater good of humanity" without his friend's consent, one would be inclined to seriously doubt that that person was virtuous.
http://jim.com/relevant.htm
Assim, não somos livres para fazermos o que quisermos. Há restrições à liberdade em seu sentido mais amplo. Importa sabermos o quanto somos livres, pois a liberdade desenfreada é utópica.
