Dylan Matthews had a fascinating piece about a young man named Jason Trigg in The Washington Post on Sunday. Trigg is a 25-year-old computer science graduate of the Massachusetts Institute of Technology who has hit upon what he thinks is the way he can do maximum good for the world. He goes to work each day at a high-frequency trading hedge fund. But, instead of spending his ample salary, he lives the life of a graduate student and gives a large chunk of his money away.

Trigg has seized upon the statistic that a $2,500 donation can prevent one death from malaria, and he figures that, over the course of a lucrative Wall Street career, he can save many lives. He was motivated to think this way by the utilitarian philosopher Peter Singer.

From the article, Trigg seems like an earnest, morally serious man, who, if he lives out his plan, could indeed help save many lives. But if you are thinking of following his example, I would really urge caution.

First, you might start down this course seeing finance as a convenient means to realize your deepest commitment: fighting malaria. But the brain is a malleable organ. Every time you do an activity, or have a thought, you are changing a piece of yourself into something slightly different than it was before. Every hour you spend with others, you become more like the people around you.

Gradually, you become a different person. If there is a large gap between your daily conduct and your core commitment, you will become more like your daily activities and less attached to your original commitment. You will become more hedge fund, less malaria. There’s nothing wrong with working at a hedge fund, but it’s not the priority you started out with.

Second, I would be wary of inverting the natural order of affections. If you see the world on a strictly intellectual level, then a child in Pakistan or Zambia is just as valuable as your own child. But not many people actually think this way. Not many people value abstract life perceived as a statistic as much as the actual child being fed, hugged, nurtured and played with.

If you choose a profession that doesn’t arouse your everyday passion for the sake of serving instead some abstract faraway good, you might end up as a person who values the far over the near. You might become one of those people who loves humanity in general but not the particular humans immediately around. You might end up enlarging the faculties we use to perceive the far — rationality — and eclipsing the faculties we use to interact with those closest around — affection, the capacity for vulnerability and dependence. Instead of seeing yourself as one person deeply embedded in a particular community, you may end up coolly looking across humanity as a detached god.

Third, and most important, I would worry about turning yourself into a means rather than an end. If you go to Wall Street mostly to make money for charity, you may turn yourself into a machine for the redistribution of wealth. You may turn yourself into a fiscal policy.

But a human life is not just a means to produce outcomes, it is an end in itself. When we evaluate our friends, we don’t just measure the consequences of their lives. We measure who they intrinsically are. We don’t merely want to know if they have done good. We want to know if they are good.

That’s why when most people pick a vocation, they don’t only want one that will be externally useful. They want one that they will enjoy, and that will make them a better person. They want to find that place, as the novelist Frederick Buechner put it, “where your deep gladness and the world’s deep hunger meet.”If you are smart, hard-working, careful and lucky you might even be able to find a job that is both productive and internally ennobling. Taking a job just to make money, on the other hand, is probably going to be corrosive, even if you use the money for charity rather than sports cars.

We live in a relentlessly commercial culture, so it’s natural that many people would organize their lives in utilitarian and consequentialist terms. But it’s possible to get carried away with this kind of thinking — to have logic but no wisdom, to become a specialist without spirit.

Making yourself is different than producing a product or an external outcome, requiring different logic and different means. I’d think you would be more likely to cultivate a deep soul if you put yourself in the middle of the things that engaged you most seriously. If your profoundest interest is dying children in Africa or Bangladesh, it’s probably best to go to Africa or Bangladesh, not to Wall Street