I could easily say that given the horror that capitalism has wrought in human history, including slavery, genocide, and fascism, it's capitalism that needs to be justified.
Capitalism rests on the premise that man is the owner of his own life and that he has a right to exist for his own sake, which means to pursue his values in his own way so long as he does not violate the rights of others. And that the fruits of his labor are his to keep and dispose of. All of the evils that you want to attribute to capitalism rest on the opposite premise, that man's life does not belong to him, that he has no right to live for his own sake but is owned by the state or the tribe or someone other than himself. And, that the fruits of his labor are not his but belong to the "collective", which really means the government, and can be disposed of without his consent.
No one alive today has ever seen a full, uncompromising, laissez-faire capitalism. So fail.
Ayn Rand rejected the value of belief in God, religion, and faith, and failed to ground her values in anything transcendent. That tends to be associated with metaphysical materialism in western culture. In addition her focus on egotism and personal pleasure is in keeping with metaphysical naturalism and materialism.
Of course, she did not ground her values on belief in God, religion, and faith. She grounded her values in reality and in the primacy of existence principle. Belief in God, religion, and faith all have their basis in the primacy of consciousness, which is a false view of reality. Honesty is the recognition that the unreal is not real and can have no value for man. But I disagree that she did not ground her values in something transcendent. The axioms and the primacy of existence are principles and as such they are conceptual in nature. Concepts are transcendent of time and space owing to the fact that measurement omission is a key part of concept formation. Time and place are measurements omitted in the process of forming concepts.
For example the concept man transcends time because it includes all men who have ever lived, live now, and will ever live. The concept man transcends place because it includes all men anywhere in all places. But if by transcend you mean supernatural, the notion of the supernatural is self-refuting and therefore, not real. The supernatural is supposed to be outside of nature, which means that it is outside the laws of nature, which means it's outside the law of identity, which means it has no specific identity, is nothing in particular, i.e., it does not exist. By its supposed nature it exists outside of nature and that's a direct contradiction.
Objectivism is not materialism. Objectivism holds that existents exist, in whatever form they exist. "Existence" is an open ended concept incuding all things that exist, their attributes, their actions and their relationships. You will not find any claims in Objectivist wrighting that say that existence only consists of material things.
Materialists deny the axiom of consciousness, Objectivism holds it as a founding principle. So let's not hear any more talk of Objectivism being materialistic. Again, do your homework.
I never said ants should be a model for human society. However, ants do prove that there's nothing unnatural about such a society.
But you are saying that. You are using it to justify collectivism in human society.
I never said it was unnatural. Everything that exists is natural. I said it is incompatible with human nature. It's perfectly compatible with the nature of ants and bees. Poison mushrooms, flesh eating bacteria and ionizing radiation exist too, but they are not good for us. Neither is collectivism because it denies individual rights. Rights are conditions of existence required by man's nature for his proper survival in a social situation.
Not all insects live in this way either. When I was a lad, I and my friends would catch an ant lion and put it into another ant lion's hole and watch them duke it out to the death. Same for doodlebugs and many other insects. There are all kinds of modes of survival and each is determined by an organisms nature. What's right for ants and bees and ant lions and fish, walruses and starfish are not right for man.
I'm challenging the false dichotomy you present: either a society is committed to extreme individualism, or it's "collectivist".
There is no false dichotomy if you read what I said. I said the two systems are based on two antithetical premises. Man either has a right to live for his own sake or he doesn't. That's a proper dichotomy. I also said that every society is a mixed case, but that the contradiction will always lead to destruction. That society can exist for a time as a mixture is not in question. But the mix always moves towards collectivism until that society ends in blood.
Look up mirror neurons and how they function some time. The scientific evidence is more complicated than you suggest.
I'm familiar with them. It does not follow from their existence that mankind thinks with one brain. This should be self-evident to you given that we disagree on practically everything.