Why Invoke the Trinity to Argue Ethics?

Michie · Jul 27, 2025

Isn't that just appealing to religious belief?

Why is always a good question. I’ll start with a question from my daughter.

My daughter aspires to be a veterinarian, and she is well on her way. She has a summer job at a vet clinic, interned at a vet clinic last summer, and visited my cousin and her husband, who are both veterinarians with their own state-of-the-art clinic, the summer before that. One of the first questions a budding veterinarian must ask herself is whether she can handle sick and dying pets. It’s one thing, my cousin told her, to love animals but quite another to see them suffering or to euthanize someone’s pet. We talk a lot about this, and the other day we had a conversation about the difference in humans and animals. She’s heard me talk about the rational soul enough to know the philosophical answer, but she was rather surprised when other people challenged her, “If we can do it to animals, then we can do it to people?” Just saying “rational soul” didn’t cut it.

I’ve had this discussion often in Catholic circles, and I always come to the conclusion that you cannot argue about ethics or morality without getting into what it means to “be human,” and you cannot do that without talking about the rational soul, and you cannot do that without invoking the Holy Trinity. I say this as a convert who was once beholden to the materialist mindset.

But, Aristotle…?

Continued below.