Zeal will do more than knowledge.

William Hazlitt, that fiery essayist of the nineteenth century, once declared: “Zeal will do more than knowledge.” In this short and thunderous phrase, he gave voice to a truth that has shaped both the triumphs and the tragedies of humanity. For knowledge may instruct the mind, but zeal stirs the blood; knowledge tells us what can be done, but zeal drives us forward to do it. Without zeal, knowledge sits like a book unopened upon a dusty shelf. With zeal, even the simplest wisdom becomes a flame that can set the world alight.

The meaning of Hazlitt’s words is clear. Knowledge is the storehouse, but zeal is the key that opens it. Knowledge may provide guidance, but zeal gives the courage to act when guidance alone would leave us timid. A man may know the path up the mountain, but if he has no zeal, he will never climb. Another may know only that the summit exists, yet with zeal he will take step after step until he stands at the peak. It is zeal that transforms thought into action, intention into reality, and weakness into strength.

The origin of this teaching lies in Hazlitt’s own spirit. He lived in an age of revolution, when the power of passion could topple kings and build republics. He watched men of great learning sit idly in parlors while others, less instructed but more impassioned, marched to change the world. Hazlitt himself was a critic of idleness, of complacency, and of the paralysis of endless thought. He valued knowledge, but he exalted zeal as the force that moves nations, ignites art, and gives birth to history.

Consider the life of Joan of Arc. She was no scholar, no strategist trained in books of war. She was a peasant girl, barely able to write, with little knowledge of the world beyond her village. Yet her zeal—her burning conviction that she was chosen by God to free her people—lifted her to command armies, inspire soldiers, and change the fate of France. Her knowledge was slight, but her zeal was a torrent that none could withstand. This is Hazlitt’s truth made flesh: zeal can do more than knowledge.

Even in the realm of invention and science, this holds true. Thomas Edison was not the most learned of men; his knowledge of mathematics and theory was often limited. Yet his zeal—his tireless drive to experiment, to fail a thousand times and yet rise again—gave the world the light bulb, the phonograph, and countless marvels. Others may have had greater learning, but few had greater zeal, and so it was Edison who brought his visions into reality.

But Hazlitt’s words also carry a warning. Zeal without knowledge can be dangerous, even destructive. Passion unguided by wisdom can lead to fanaticism, to reckless acts that harm rather than heal. The crusader must be tempered by counsel, the reformer guided by truth. Yet when zeal and knowledge walk together, nothing is impossible. It is the fusion of the two—the fire of zeal with the lamp of knowledge—that creates greatness.

The lesson for us is simple and powerful: do not wait until you know everything before you act. Do not let the lack of perfect understanding paralyze you. Begin with what you know, but let zeal be your companion, for it will carry you further than knowledge alone. Learn, yes—but also dare, strive, and persist with passion. For history does not remember those who knew much but did nothing; it remembers those whose zeal moved mountains.

So what must you do? Cultivate zeal for what is just, for what is true, for what is noble. Temper it with knowledge, but never let the hunger to act be smothered by endless hesitation. In your studies, in your work, in your calling—let zeal drive you beyond what you thought possible. For as Hazlitt teaches us: “Zeal will do more than knowledge.” And those who burn with righteous zeal, even with modest knowledge, may leave behind a legacy greater than the wisest who never dared to act.