Put off your imagination, as you put off your overcoat, when you

“Put off your imagination, as you put off your overcoat, when you enter the laboratory. Put it on again, as you put on your overcoat, when you leave.” — thus declared Claude Bernard, one of the great fathers of modern physiology. Within this vivid metaphor lies a discipline of the mind that every seeker of truth must learn. Bernard’s words are not a rejection of imagination, but a reverent honoring of its proper place. For imagination, like fire, is both sacred and dangerous — it can illuminate the world or consume it entirely. The wise must learn when to lay it aside and when to wear it again, as one guards the balance between reason and wonder.

To “put off the imagination” in the laboratory is to enter the temple of science clothed in humility and precision. There, the seeker must be free from the fever of fancy, from the seduction of assumption. Facts, like delicate jewels, must be handled with clean hands — untouched by the stains of desire or expectation. The scientist who clings to imagination while experimenting is like a sailor who trusts the stars but ignores the compass. Bernard reminds us that discovery begins not in fantasy but in discipline — in the quiet observation of what is, rather than the restless longing for what should be.

And yet, when the door of the laboratory closes behind him, the wise scholar must once again “put on the imagination” — for without it, knowledge remains a pile of stones, never a cathedral. Imagination breathes life into data; it transforms cold observation into vision, and mere analysis into revelation. To imagine is to see the invisible patterns that bind all things, to glimpse the divine order behind the veil of phenomena. Bernard’s teaching, then, is not a denial of imagination, but its sanctification: use it not in the act of discovery, but in the art of understanding.

Consider the story of Isaac Newton, who once watched an apple fall from a tree. In that single moment, imagination and reason stood side by side. His mind observed what was — the apple descending — but his imagination asked, why must it fall? From that union, the law of gravity was born. Had Newton been ruled only by fancy, he might have dreamed without proof. Had he been guided only by logic, he might have measured without meaning. It was the rhythm of both — the removal and return of imagination — that allowed him to unveil the laws that govern the cosmos.

So too in every field of thought, the dance between discipline and imagination must be carefully tended. The artist who never restrains his vision becomes lost in chaos; the scientist who never dreams becomes a prisoner of facts. To know when to set imagination aside is wisdom; to know when to reclaim it is genius. For in truth, imagination and reason are not enemies but companions — one gives birth, the other gives form.

Bernard’s metaphor also holds a moral lesson beyond the walls of the laboratory. In life, as in science, there are moments when we must strip away illusion and confront reality as it is — unembellished, unsoftened. This is the time for clarity, for discernment, for truth. But afterward, when the facts are known and the trials endured, we must again clothe ourselves in imagination, for it is imagination that restores hope, meaning, and beauty to existence. To live without imagination is to live without sunrise, without poetry, without the song of the soul.

Thus, the teaching is clear: be both dreamer and disciple. Enter your work with the precision of a sage, but leave it with the wonder of a child. When you study, remove your overcoat of imagination — keep your mind cool, your thoughts pure. But when you return to the world, put it back on — let your vision warm your heart and guide your purpose. This balance is the secret of creation, the unity of knowledge and spirit.

So, remember Claude Bernard’s wisdom: truth and imagination are twin wings of the same being. To use one without the other is to limp through life. Wear imagination as your garment of inspiration, but remove it when you seek the naked truth. Then, when the truth is found, wear it once more — and let it carry you beyond the known, toward the endless frontier of what might be.