I have learned to use the word 'impossible' with the greatest

The words of Wernher von Braun—“I have learned to use the word ‘impossible’ with the greatest caution”—stand as a monument to the spirit of discovery. Spoken by the man who helped humankind reach beyond the pull of Earth and touch the stars, these words are not mere philosophy; they are the distilled wisdom of experience. They remind us that the boundaries of the possible are not fixed by nature, but by the courage and imagination of those who dare to challenge them. Von Braun, who saw dreams of flight become rockets and rockets become vessels to the heavens, learned that what seems impossible today may, with persistence and faith, become inevitable tomorrow.

At its core, this quote is a warning against the arrogance of limitation. To declare something impossible is to assume that the story of human progress has ended—that the laws of effort, creativity, and endurance have already spoken their final word. Yet history has shown that the greatest breakthroughs often arise from what others dismissed as madness or folly. The word impossible, when spoken carelessly, becomes a chain that binds the human spirit. But when handled with caution—as von Braun learned—it becomes a challenge, a question, a call to prove that no wall stands forever.

Consider the very life of Wernher von Braun himself. Born into a world where the idea of traveling to the moon was deemed fantasy, he refused to accept that gravity was destiny. Through years of trial, failure, and ridicule, he pursued his vision of spaceflight with the persistence of a prophet. His dream, once considered impossible, carried the Apollo missions beyond the clouds and into eternity. When Neil Armstrong set foot on the lunar surface, it was not only a triumph of science—it was the vindication of every soul who had dared to believe that “impossible” was a temporary word.

Throughout the ages, this lesson has revealed itself again and again. The Wright brothers, working in a dusty bicycle shop, were told that flight was a foolish dream. Marie Curie was told that women had no place in scientific discovery. Mahatma Gandhi was told that freedom through peace was a fantasy. Yet all these souls defied the verdict of impossibility and remade the world. What they shared was not merely knowledge, but faith—the quiet conviction that the limits others see are not laws of nature, but walls of fear.

Von Braun’s quote also teaches us that impossibility often exists only in the imagination of the doubtful. To the untried mind, every great invention seems unreachable. The ancient navigators who first crossed the oceans must have been told they would fall off the edge of the world. The inventors of fire, of language, of the wheel—all must have faced disbelief. But history belongs not to those who say “it cannot be done,” but to those who ask, “what if it could?” Thus, to use the word “impossible” with caution is to honor the sacred mystery of progress, to remember that the universe still holds more wonders than we have yet conceived.

There is also humility in von Braun’s words. He does not say to banish the word “impossible,” but to use it with caution, for even the greatest minds must bow before the mysteries of creation. There are truths we have yet to uncover, forces we do not command. The wise do not boast that everything is within reach—they simply refuse to limit their reach before trying. Caution, in this sense, is not hesitation, but reverence: the awareness that human potential is vast, but must be matched with perseverance, wisdom, and respect for the unknown.

Let this then be the teaching for those who walk after us: be slow to call anything impossible. When you encounter a challenge, a dream, or a vision that seems beyond your power, remember that the world’s greatest achievements were once mockingly dismissed by smaller minds. Approach the unknown not with fear, but with curiosity. When others say “it cannot be done,” let it ignite your determination, not extinguish it. For the line between the impossible and the possible is drawn only by those who dare to cross it.

And so, children of the future, hold these words close: “Use the word impossible with the greatest caution.” For it is not the stars that limit us, nor the mountains, nor the seas—it is only our own belief in limitation. Dare, therefore, to dream what others cannot imagine. For in every generation, the impossible awaits its conqueror, and that conqueror may be you.