I liked this, from a reader:

You wrote;
“Once someone becomes disillusioned with the cause they’ve signed up for, it’s axiomatic that the cause no longer provides happiness or meaning.”
Okay, but what about marriage. My wife expects more of me than a vow to hang around until my marriage no longer provides happiness or meaning for me. My vow was not, I love you today, therefore I am marrying you. It was rather, I am marrying you, therefore I promise to keep loving you.
And what if it’s 1863, the war is going badly and, quite frankly Mr. Lincoln, a lot of just want quit now.
Wilkinson says something really important when he says ;
There are some things some people are going to do no matter what. So that’s what I think those people should say: “I am going to do this no matter what.”
To which I would only had that if the thing you are going to do do no matter what is rape and pillage, well, then I’m going to fight you no matter what.
As Wittgenstein put it, explanations have to stop somewhere.

Good points. And perhaps, I was too glib there. But I think the issue here is what we mean by “disillusioned.” Mere frustration or temporary exhaustion is not necessarily what I had in mind by “disillusioned.” Moreover, meaningful commitments are, well, meaningful. If you enlist or you get married (“but you repeat yourself!” — The Couch), you are pursuing something that will be require sacrifices and hardships of one kind or another and those hardships and sacrifices in turn make the whole thing more meaningful. We could also talk about leaps of faith, but I’ve got a column deadline.

As for rapists and pillagers, there are many responses to that. But the easiest one is that raping and pillaging violates the rights of others to pursue happiness and is against even the most minarchist and even anarchist notions of the just society.

Update: And then there’s this from a longtime liberal reader:

Dear Jonah,
I can’t resist taking on some of the points you raised in your post on happiness. If Murray is right that the founders meant “happiness” in an Aristotelian sense, surely they understood happiness as a morally laden concept that has to do with citizenshipand a clearly defined conception of the good life within a culturally limited community. This is precisely the opposite of what you take happiness to mean: whatever one thinks is meaningful. Whereas your conception of happiness is subjectivist and relativist, the Aristotelian conception is an objective, shared, social conception. The Aristotelian version finds its modern voice in Alisdair MacIntyre, and other communitarians on the left and the right. The classical liberal understanding of happiness, which I think you share, is expressed by people like Nozick or Rawls.
I’m not sure why Murray thinks that Hamilton, Madison, and Jay meant happiness in an Aristotelian sense. It’s more likely they meant it in a classical liberal sense, given that the Federalist Papers are grounded in the liberal vision of an empirical “science of politics,” not in a civic-republican understanding. But, either way, it’s worth pointing out that you and Murray are in fact at odds about what the Founders’ understanding of happiness is, rather than on the same page. Aristotelian happiness is about as far aways from the happiness of classical liberalism as you can get.
Doubtless there are republican and liberal elements mixed together in the American founding, and they play out across our various intellectual traditions, from classical liberalism, to civic republicans, to, conservatism to pragmatism, to progressivism. Ultimately, it’s difficult to maintain the relativistic conception of happiness you propose, because its vulnerable to criticism from the left and the right. Those on the right will say will say that happiness has to do with a particular conception of the good life, involving heterosexual marriage with children, christian moral values, etc. And they will argue that the law does, and must, enshrine those principles. Those on the left will say that the liberal conception of happiness actually smuggles in a narrow vision of happiness, based on relations of property, which justifies inequality with the insurmountable principle of free contract. Both of these criticisms have some merit. At the end of the day, the law has to make some judgments that shape people’s understanding of happiness. Whether those judgments are explicitly proclaimed or not is less important than what the law permits and doesn’t. Those legal boundaries set the limits of our moral universe. So, its impossible to live in a political society where personal happiness and meaning are innocent of political meaning and power. Happiness and meaning are unavoidably determined by political and legal action. That’s why rational debate over the content of legislation is so crucial.

More on this later. Must . . . finish . . . column.