Famous philosopher Kant revealed the simple test that shows if somebody is a 'good person'

What makes someone a genuinely good person? Although there's a lot to factor in, one idea from philosopher Immanuel Kant, shared by creator Julian de Medeiros, still feels relevant today. In a TikTok video on Mederios' TikTok page @julianphilosophy, which has gained 3.3 million views and more than 263k likes, he shared, "Here’s a simple sign that somebody is a good person, that they are a kind-hearted individual, and it’s a beautiful little theory from the philosopher Immanuel Kant, who observed: we can judge the heart of man by how he treats animals."

As per Medeiros, Kant wrote that "for a man who is cruel to animals will also be unkind in his dealings with men." Medeiros explained, "You can observe how people treat animals, and thereby make a judgment as to their character." He added that Kant wasn’t the only one to make this connection. "In fact, the German poet Goethe wrote something similar. He said a man who is cruel to animals cannot be trusted, for in his cruelty to animals he reveals his inner nature." Julian closed the point with, "A good person treats animals well, is kind to them, enjoys their company, and therefore has the kindness and patience to be a good friend and a partner to people as well. That’s a sign."

Modern psychology gives weight to these centuries-old ideas. Research shared by Animal Legal Defense Fund has found a strong correlation between cruelty to animals and violence toward humans, whether against children, partners, or vulnerable individuals. A 2025 study published by Laurent Bègue, Serge Garcet, and David Weinberger surveyed more than 55,000 people in France and found that 6.4% admitted to harming animals, and those respondents were far more likely to show traits like callousness and impulse control problems. Other studies highlight that cruelty to animals is often an early warning sign of violence against people, with psychologists noting the overlap between animal abuse, domestic violence, and broader antisocial behavior.

Many viewers strongly connected with the message and shared their own perspectives in the comments. @hunter_2990 said, "I think this is one of those things that only applies in one way: cruelty towards animals will also translate into cruelty towards humans." @lisabry1964 wrote, "My dad always said, 'Watch how people treat animals, children, the disabled, and elderly. That will tell you all you need to know about them.'" @courtneyoatesxx commented, "Animals are mostly innocent and defenseless. So how some people interact with animals has always been very telling to me also." @mrfifty1 added, "Simple. The level of selflessness vs selfishness is the spectrum in which we measure morality."

However, some didn't get behind the idea. @italia.mel chimed in, I don't think this is true. In Italy, I have met people who love animals more than humans." @theseekers.lamppost shared, "I used to believe this until I worked with a person who was cruel to animals, as he was taught they were not useful nor important until he knew better. Most people can change when their hearts open." @karinarios809 pointed out, "I think someone who is cruel to animals is definitely bad; however, respecting natural life does not make them good either." 

You can follow Julian de Medeiros (@julianphilosophy) on TikTok for more philosophy content.

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