Chapter 7: The Mental Modules That Run Your Life

When I was a freshman in college, I learned that I had an intertemporal utility function. This wasn’t a diagnosis; “intertemporal utility function” isn’t a malady. It’s something everybody has. It’s an equation that describes, roughly speaking, your willingness to delay gratification—your willingness to forgo something you like in order to have more of that something later.

So, for example, I might be willing to give up $100 in wages today if I could be guaranteed that I’d get $125 a year from now. But my friend, whose intertemporal utility function is calibrated differently, might demand $150 a year from now in exchange for giving up $100 now.

This is also called “time discounting.” People tend to “discount” the future in the sense of feeling that getting $100 a year from now isn’t as good as getting $100 today. In the example above, my friend discounts the future more steeply than I do.

Anyway, according to the models presented in my economics class, however my intertemporal utility function was calibrated—however steep my time discounting—it would stay that way tomorrow and next week and next month and next year. My discount rate was said to be a firm and enduring feature of my psychology.

I think the Buddha would have been skeptical of this claim. He tended not to see things as enduring—certainly not things that are part of a person’s psychology. I think if he had been my college classmate, he would have stood up during an econ lecture and said, “What do you think of this, O monks? Are mental formations permanent or impermanent?”

Actually, he might not have been quite that disruptive. But according to Buddhist scripture, he did say that very thing in another setting. It was during one of his not-self sermons. In fact, it was during his very first and most famous discourse on not-self, the one we looked at in chapter 5. In that chapter and chapter 6, I focused mainly on only one part of the Buddha’s basic not-self argument: the idea that the “five aggregates” are not under your control; they do not, as he later put it, bear the relationship to you that a king’s domain bears to a king.

The other big part of the Buddha’s not-self argument, the part I touched on only lightly, was about flux, impermanence. After he asks the monks “Are mental formations permanent or impermanent?” he gets the predictable reply: “Impermanent, O Lord.”

Well, the Buddha goes on to ask, does it make sense to say of impermanent things “they are mine, this I am, this is my self”?

“Indeed, not that, O Lord.”

The Buddha then goes through the same drill with the other four aggregates. He insists, in each case, that something subject to change shouldn’t be thought of as part of the self. He doesn’t explicitly say why. And to provide the fullest explanation, we’d need to delve into ideas about the self that were circulating in his day. But certainly, leaving his intellectual context aside, there’s a kind of commonsense appeal to his argument: We do tend to think of the self—the inner, real me—as something enduring, something that persists even as we grow from children to adults to senior citizens.

But in fact, of course, we change. And we don’t just change in the sense of changing from children into adults. We change on a moment-by-moment basis. And sometimes we change along dimensions that are commonly thought to be constants….