One of the things cognitive science teaches us is that when people define their very identity by a worldview, or a narrative, or a mode of thought, they are unlikely to change-for the simple reason that it is physically part of their brain, and so many other aspects of their brain structure would also have to change; that change is highly unlikely.

In all aspects of life... we define our reality in terms of metaphors and then proceed to act on the basis of the metaphors. We draw inferences, set goals, make commitments, and execute plans, all on the basis of how we in part structure our experience, consciously and unconsciously, by means of metaphor.

For centuries, we in the West have thought of ourselves as rational animals whose mental capacities transcend our bodily nature. In this traditional view our minds are abstract, logical, unemotionally rational, consciously accessible, and, above all, able to directly fit and represent the world. Language has a special place in thie view of what a human is - it is a privileged, logical symbol system internal to our minds that transparently expresses abstract concepts that are defined in terms of the external world itself.

We categorize as we do because we have the brains and bodies we have and because we interact in the world as we do.

Barack Obama understands what Ronald Reagan learned, which is that people vote not on the basis of issues and policy details, but on the basis of something deeper, namely, what are your values? Are you authentic? Do you say what you believe? Do you communicate with us? And do we identify with you? You don't know what particular issues are going to come up in the future, so you have to depend on someone's values, and whether they are telling you the truth, and whether you can trust them in office. Obama's been running a campaign on that basis.

The essence of metaphor is understanding and experiencing one kind of thing in terms of another.

We now know, from the latest research about neurons, that we are hard-wired for empathy. We're hard-wired for cooperation. That is something about what we are as people - what it means to be a human being. And what Barack Obama was addressing was not just race or just the nature of politics. The great speeches address who we are as people, what it means to be a human being.