Science Quote by Walter Reisch

Defiant certainty is doing the heavy lifting here. “This I know” isn’t a preface so much as a shield: a blunt claim of knowledge in a world where knowledge is usually provisional, argued over, revised. Reisch frames what follows as one of the few statements sturdy enough to survive doubt. That’s a scientist’s move, but it’s also a rhetorical flex, borrowing the authority of empiricism to certify something that can’t be measured.

“The spirit of Man” has an old-fashioned grandeur, deliberately capitalized in meaning even if not on the page. It’s not “people,” not “society,” not “humanity” in the contemporary, inclusive register; it’s “Man” as archetype, a species-level protagonist. That choice telegraphs a certain era and worldview: humanism with a steel backbone, the kind forged in the 20th century’s cycles of catastrophe and recovery. You can hear the implied adversary in the passive construction: cannot be stopped by whom? War, tyranny, poverty, censorship, disease, bureaucracy, history itself. The sentence refuses to name the obstacle because it wants the claim to scale.

What makes the line work is its strategic vagueness. “Spirit” is elastic enough to cover scientific curiosity, moral courage, artistic invention, even stubborn survival. And “cannot be stopped” is absolute, almost reckless, which is precisely the point: the quote isn’t offering a forecast so much as issuing a vow. In a scientific context, it reads like a reminder that inquiry is a form of resistance; you can shut labs, silence papers, exile minds, but you can’t extinguish the underlying human itch to understand and remake the world.