Here's
my old thread on the subject, if you're interested. (Not everything I say there I still agree with.)
I read the book that Perfection mentioned, and I agree with Shermer that
Objectivism (big O) is a full-fledged cult that worships Ayn Rand. But
objectivists (small o) that feel free to disagree with Rand at times---newfangle is one, or at least was once one---can be perfectly reasonable people.
While Objectivism's value of reason and its other "basics" (its epistemology and metaphysics) are admirable, its ethics and politics start getting messy.
One problem: Donating to charity, for example, can supposedly be in your self-interest if it makes you feel good. "Self-interest" as Objectivists describe it is thus a useless term. If I don't act in my self-interest, what the hell am I doing?
TLC pointed out another problem: If I'm supposed to be so concerned about my self-interest, why should I limit myself by being concerned with others' rights to liberty and property? Sure, in many cases respecting those rights is in my interest, but in other cases it's not. (And even if I could never think of a case where it weren't, it still wouldn't make sense to think of rights as rules instead of suggestions.)
Another problem: If I'm a nice little Objectivist that believes my self-interest is the highest good, why should I go around telling people to act in their self-interest? Why shouldn't I tell them to bow down before me?
(I guess, going back to problem number 1, the WillJ slaves would actually still be acting in their self-interest.
) (Objectivists sometimes respond to this with misunderstandings of Adam Smith's principle of the market's invisible hand.)