How you arrive at the conclusions may be another interesting question, but mine specifically meant "what justifies this?" You may have arrived at a very strict stance on freedom of speech, for instance, through reading/debate/etc, but what justifies that freedom of speech?

If the core answer really is the biological impulse to survive and function together and the assumption that this survival is good, then where do complicated philosophical issues fit in? Do they end up back at this point, just in a much more complicated, far-reaching way? Or is there some other reason which makes THESE kinds of things good, which has nothing to do with survival? If there is, what is that?