This classic Victorian novel in many ways represents an attack on a way of life that becomes increasingly demarcated by industrialisation. This is shown to affect every sphere of life, including education. The danger of this wide-scale adoption of industrialisation is that it has the potential to turn flesh and blood human beings into nothing more than machines or functioning parts of a machine by the deliberate warping and frustrating of their imaginations and creativity. Note how two of the chief characters demonstrate this: Bounderby treats his workers as mere objects that can be discarded at whim and Gradgrind teaches his charges the enlightening approach to fact alone.
The approach to education is summarised most humorously to my mind in Chapter 2, entitled "Murdering the Innocents." In this chapter the children in his school are described as "little pitchers before him, who were to be filled full of facts." However, his attempts to educate are slightly frustrated in this Chapter by Sissy Jupe, who throughout the novel seems to symbolise the power and triumph of emotions, and her inability to define a horse, which Bitzer helpfully defines as:
"Quadruped. Graminivorous. Forty teeth,namely twenty-four grinders, four eye-teeth, and twelve incisive. Sheds coat in the spring; in marshy countries, sheds hoofs, too. Hoofs hard, but requiring to be shod with iron. Age known by marks in mouth."
Ironically, Mr. Gradgrind then says to "Girl number 20" (Sissy) that she now "knows what a horse is," even though she has worked with them all of her life.
Thus what Dickens is protesting against is a society and an education system that treats human beings as nothing more than cogs in one grand, massive machine that behave and are governed entirely by a system of rules that suggests that human beings can be quantified, understood and that their behaviour is predictable. It is this that Louisa protests against by leaving Bounderby and finally she is able to confront her father and make him see how his method of education has caused her great unhappiness.