The widespread reluctance to acknowledge (let alone to explore or elaborate) how deeply we remain embedded in "animal" life has serious practical consequences, as it accelerates our destruction of the world we commonly inhabit. This is obvious in the sense that our failures of identification with other species remove barriers to violence and rapacious exploitation; it is less obvious in our expectation that "uniquely human reason" will rescue us from our own greedy appetites. We wishfully suppose ourselves ennobled by our comparatively well-developed cortices, but the reasoning (or rationalizing) power supplied by those wrinkly blankets obfuscates as much as it elucidates; it has made us masters at self-deception.
Jonah Lehrer makes the excellent point (in Proust Was a Neuroscientist) that the neocortex, in its very novelty, may be regarded, should be regarded as less developed than supposedly more primitive parts of the brain-- there hasn't been time to smooth out its kinks, or make its wrinkles perform most efficiently and effectively (that is to say, most adaptively). It remains fundamentally less reliable than older structures, though the dialogue that ensues between them has clearly been productive in the (geologically) short term: it has allowed us to overrun the planet. Yippee.
This is my point: the emanations of the neocortex (e.g. reason and faith) have not yet produced any notable constraint on our "animal" compulsions to consume and procreate, and to expect that they ever will is patently ridiculous, when our brains have been "designed" bottom-up for the opposite purpose. Even our most hopeful discoveries in neurology (of mirror neurons, for example, with their strong suggestion of a built-in capacity for empathy) can only embellish the fact of our dominant hunger, that is, to live beyond ourselves in the proxy of our genes. That superobjective (says the theatre gal) spawns an astonishing variety of more trivial hungers in day-to-day life, few of which consent to be curbed by reason or faith (though both propose compelling accounts of why other people's appetites should be suppressed or refused outright). Even those of us who have abdicated our procreative vocation find alternative modes of proliferation (hello, blogosphere!), and our consumption continues apace, as if we were not genetic dead ends (and indeed we may not be, if we help our nieces, nephews, or cousins to thrive).
Yes, this is to say that I am extremely pessimistic about our ability to pull ourselves by our elastic bootstraps into an enlightened state-- of mind or self-government. But if we do, the mechanism will not, I think, be reason or faith. I think it will have to be pleasure, unless it is desperation. If we cannot channel our appetites in less destructive directions (e.g. by encouraging people to remain "selfishly" childless, by cultivating our inner resources and capacity for pleasure), we will sprint ever faster toward that great brick wall of finitude.
I'm pretty sure it's already too late, at least for anything like the life I happen to lead (the outrageously wasteful kind). But crisis is normal in the long life of the planet. The dinosaurs never dreamed of us, and we can't imagine what (or who) will flourish when we're gone. I can still rage against the dying of the light in my visible spectrum-- the snuffing of lives I am disposed by evolutionary accident to cherish.