Oh, no, we didn't come from nowhere, there's all kinds of elements that get involved there, namely hydrogen and genetics, but of course, you don't believe in evolution, so it doesn't matter. Regardless, this isn't a duscussion about evolution now is it?
Now, humans have a built-in series of psychological mechanism that govern what we call morality. We can obey and disobey it as much as we want, but it's all relying on primal instinct and experiences, (I.E. how one feels about something based on what's happened to them, and the things they've been taught before). You'll notice that these consicence-oriented decisions are pretty much absent in people with sociopathy, and so they can do pretty much anything they want without feeling bad about it later. But nevermind that. However, your statement that We're elements of chance and therefore he can't trust his own thinking is moot. The fact is, chance is a definite system, probability has a definite mechanism to it, (see Quantum Mechanics for details.) There's a mathematical order to pretty much everything under the sun and beyond. There's an order to it, and while we could be "beings of chance" it doesn't mean we're random in any sense of the word, it means there was a possibility for us to exist, and at one point that possibility was fulfilled.
