Gradgrind is a middle-class businessman and later a Member of Parliament. More importantly, he is the owner and operator of the educational system Dickens is dead set against. Grandgrind's system is based on the idea that only facts, math, and the measurable are important. He thinks that touchy-feely things like emotions and creativity should be repressed. Gradgrind not only raises his own kids according to his theory, but also makes sure that the school children taught by Mr. M'Choakumchild have it drilled into their heads as well.
However, as he finds many years later, if you don't teach morality, the kids won't learn morality. And so Gradgrind's comeuppance is extremely appropriate (of the eye-for-an-eye variety). Everyone who has excelled at Gradgrind-directed studies ends up betraying or letting him down in a shattering way. His daughter Louisa makes a terrible marriage, almost has an affair, and ends up separated and childless. His son Tom becomes a thief and frames another man for his crime. In the final kicker, Bitzer, the model student, refuses every appeal for mercy and gratitude from his old headmaster. Instead he just quotes Gradgrind's own materialistic and selfish philosophies back to him.
Still, what seems interesting is that Gradgrind doesn't himself live according to his worldview. He is generous – for instance, he accepts Sissy into his school and lets her live at his house when her father abandons her. He is a lot more tolerant and empathetic than other fathers of the time would be toward a near-adulterous daughter. We see him immediately take Louisa in and encourage her to be apart from Bounderby. And by helping Tom escape from justice without hesitation, Gradgrind shows that he believes that his duties as a father outweigh whatever he might owe the nation as an indifferent citizen.
In the end, Gradgrind is actually able to see how wrongheaded his approach has been. He changes his attitude and behavior to the point that he is ostracized by members of his party in Parliament. Why do you think this is? Gradgrind is the poster-boy for the strict school of thought that the novel seems to be demonizing. What is the reader to make of the fact that he actually turns out to be a fairly decent human being?