Reason

Ben Franklin said concerning reason: "So convenient a thing is it to be a reasonable creature, since it enables one to find or make a reason for everything one has a mind to."

Now, Big Frank, was thinking the hinge there in Franklin's quotation was what "one has a mind to". Reason is utilitarian, its job is to do your bidding. It starts early - just ask a kid why the sky is blue, or why water is wet, or any other question and they will give you an answer. Look out at a beautiful scene in nature and ask yourself why it is that you like it - you'll get an answer, but it probably has little to do with why you were asthetically pleased. Ask yourself why you are in love with someone (there is no reason for that - one loves whom one loves) and your reason will supply you with a laudry list of characteristics and traits - none of which, most likely have anything to do with your attraction.

There have been studies on this. People are asked difficult questions, like whether the minimum wage should be increased. Most people have an immediate preference, and then they call their reason lawyer to supply them with some support. Reasons doesn't decide it backs up the position or preference that the person alreay has. Where does that preference come from - who knows?