Many in contemporary Western society believe that biology explains all that we are...all that makes us human. They see us as more (or less) evolved than animals, and simply the product of our DNA. The view that we're nothing more than our biology generally falls under the category of Philosophical Naturalism.

When discussing morality with philosophical naturalists, atheists often make the claim that morality is defined by society, rather than by any universal external standard (like the nature of God). This claim, when you boil it down, is ridiculous: it's nothing more than personal opinion on a larger scale.

Every time I pin down someone who claims that there is no God - and thus no objective right or wrong - they admit that they're being inconsistent when they judge the actions of another to be wrong. They don't seem to mind being inconsistent, which bothers me. It's like pretending that you're two feet taller than you actually are...everybody can see right through it.

This video depicts a serial killer debating a college professor. The doc teaches that the disposition to violence is genetic, while the killer takes the opposing view. Not for little kids, of course.