Tom is Louisa's brother, and is raised in the same manner that she is. He ends up a degenerate gambler who robs Bounderby's bank to pay his debts. Tom then has to be smuggled abroad in order to avoid going to prison. After many years in exile, he becomes remorseful, but dies on the trip back to England.
If Louisa is the kid who could have turned out differently, Tom is the worst-case scenario for what happens when morality and emotional maturity are skipped over in favor of facts in early childhood. In other words? When we first meet him, he starts out a cowardly jerk. Later, when he is shipped off abroad to escape prison, he has become a cowardly, jerky, selfish thief.
In a way, Tom might be an even better argument than his sister about why facts-only educational systems are such a bad idea. Let's work it out together. To make a reasonably well-adjusted human being, the natural inclinations that a person is born with need to be molded carefully by that person's environment and education. Take Louisa for instance. She's just naturally caring. Unfortunately, she does end pretty badly as a result of her upbringing, but she doesn't hurt anyone in the process. Unlike his sister, Tom's natural tendency is to only look out for numero uno. The education his father molds him with only gives Tom an excuse for pure, unadulterated self-interest.
Tom's education gives him an explanation for why it's OK to only look out for himself. Actually, not just an explanation, but a logical justification! So, Tom goes through life trying to advance his interests and get ahead by using and abusing other people. He guilt-trips his sister into marrying Bounderby so that he can be slightly better positioned at the bank. Tom also makes friends with Harthouse and tells him all of Louisa's secrets because he is psyched to be in the same room with the novel's version of the prom king. To top it all off, he frames Stephen for the bank robbery just because he sees the opportunity to do so. We're guessing that if Tom had learned a little more about generosity and charity, he wouldn't have ended up a criminal. So he probably wouldn't have ended up being Mother Theresa, but perhaps with a different upbringing Tom might've lived his life with a little more compassion.