This article was originally published on April 5, 2017.

The summer my brother Duane turned twenty, a formidable young man stayed with us on a break from the Ivy League. He had never, to anyone’s knowledge, lost an argument. Several weeks into his visit, my mother walked into the dining room where my brother and his friend were, in theory, eating lunch. In reality, both men were sitting at the table with locked jaws. One didn’t have to say, “I need you to eat.” The other didn’t need to say, “Hell, no.” They both knew exactly what was going on: the Ivy Leaguer was losing an argument to my brother, who had never learned to speak.

Duane was born healthy, as far as anyone could tell, but when he was three months old he was attacked by his first grand-mal seizure, with countless more to follow. He was diagnosed with Lennox-Gastaut syndrome, a rare form of epilepsy, and his seizures were so brutal that the doctors didn’t think he’d live out the year. That one year turned into thirty-one and a half.

Often when I tell people about my brother, I see questions in their faces: “Why was he ever born? Why put him through needless suffering? Why dedicate your family’s time and energy to a hopeless case? Why spend all that money?” These questions reflect a worldview so widely accepted today that most people don’t even realize they hold it: that of utilitarianism. Yet its principles are constantly invoked in debates over right or wrong, for instance in regard to abortion or physician-assisted suicide.

Most famously advanced by John Stuart Mill, utilitarianism argues that an action is good only because it maximizes a given benefit. This school of thought’s most prominent champion today is the Australian philosopher Peter Singer, a professor of bioethics at Princeton University. In Singer’s version of utilitarianism – which is in many ways just an especially forthright articulation of our culture’s worldview – to act ethically means to seek to maximize the satisfaction of people’s desires. This, in Singer’s view, also means that we must seek to minimize the suffering of people unable to have or express preferences – if necessary, through terminating their lives before or after birth. People such as Duane.

In 1980, the “save the children from existing” philosophy hadn’t reached southwest Pennsylvania, where my parents lived. And before Duane’s birth, they had no idea there was anything different about him. But if they had known, I know what my parents would have said: “He’s our son.”

Nobody knows how much Duane could understand. In one aptitude test, he showed no interest in differentiating a red square from a yellow triangle, and the neurologists told us that he had the cognition of a three-month-old. We were amused. How do you measure intelligence in someone so full of life, whose constant seizures played havoc with his memory and situational awareness? Snapshot neurological tests can’t capture the reality of his life.

Can Singer or other utilitarians do any better than the neurologists? For many in this camp, not all members of the human species are considered persons. Personhood, they argue, requires self-awareness and the ability to conceive of future goals and plans: to experience oneself as having interests. Duane would not have qualified. In his case, utilitarianism would say that another good – reducing suffering – should have kicked in. No doubt Singer would allow that my parents’ preference to keep Duane alive should have weight (after all, they are “persons,” even if he supposedly wasn’t). But still, by Singer’s account, there was nothing in Duane himself that could have made it wrong to kill him.

Christians do not think like this. In Christian terms, an action is good not only because it has beneficial consequences, but because it is good in itself. What’s more, good actions have the power to change for the better those who do them. We seek to love like God – to be merciful, honorable, and just – because we want to reflect his character: to “become like Christ,” to grow into “the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ,” as Paul writes in his letter to the Ephesians. It is this becoming that guides our decisions, because all choices change us – in one direction or another.