What is simple is false and what is not is useless. -- Paul Valery
—What lingers after this line?
One-minute reflection
What's one small action this suggests?
A Razor-Edged Warning About Thinking
Paul Valéry’s line compresses a lifelong skepticism into a single dilemma: if an explanation is too simple, it distorts reality; if it captures reality’s full complexity, it becomes unusable. The quote therefore isn’t merely cynical—it is diagnostic, describing the constant tension between accuracy and practicality that shadows every attempt to understand the world. Rather than offering a neat rule, Valéry forces the reader to sit inside an uncomfortable trade-off. From there, the aphorism nudges us to ask a better question than “Is this true?” or “Is this useful?” Namely: “How much simplification can I afford without lying, and how much complexity can I tolerate without paralysis?”
Simplicity as a Form of Untruth
To say “what is simple is false” is to accuse simplicity of leaving out the very variables that make a claim reliable. A simple story often functions like a map with too few landmarks: it feels clear precisely because it has erased obstacles, exceptions, and competing causes. In public debates, this is why slogans thrive—they give the mind a clean handle, even when the handle is attached to an inaccurate picture. This suspicion echoes Alfred Korzybski’s reminder that “the map is not the territory” in Science and Sanity (1933): our summaries are not the thing itself. Valéry’s point follows naturally: when the summary becomes too sleek, it stops pointing to the real terrain.
Complexity That Can’t Be Lived With
Yet Valéry’s second clause—“what is not is useless”—turns the knife. A fully qualified account may be so tangled with conditions that it cannot guide action. Consider medical consent forms or legal contracts: striving for completeness, they become so dense that ordinary people cannot actually use them to decide. Even in everyday life, a perfectly nuanced answer to “Should I change jobs?” might require a model of finances, psychology, labor markets, and family dynamics so elaborate that no decision ever gets made. In this way, the quote suggests that total truth can be inert. An explanation may be accurate in principle and still fail as a tool for living.
The Narrow Bridge Between Truth and Use
As the two halves meet, Valéry implicitly defines thinking as an act of compromise: we build models that are “false” in the sense of simplified, but “useful” in the sense of enabling judgment. This aligns with George E. P. Box’s well-known formulation in statistics, “All models are wrong, but some are useful” (often cited from his 1979 writings). The bridge is narrow because both sides are hazards—too simple and you mislead, too complex and you stall. Consequently, wisdom becomes less about finding a perfect statement and more about calibrating a statement to its purpose, audience, and stakes.
Context Determines the Right Level of Simplicity
The quote becomes most practical when we treat “false” and “useless” as context-dependent. A pilot’s checklist is a deliberate simplification of aeronautical reality, but it is the right simplification for safety-critical action. By contrast, that same checklist would be “false” if used as a complete theory of flight. Similarly, an academic model might be “true enough” for research yet “useless” for a policymaker who must decide by Friday. Seen this way, Valéry is not condemning explanation itself; he is demanding that we match our level of detail to the decisions we need to make, while staying alert to what our simplifications hide.
A Practical Ethic: Humility and Revision
Finally, Valéry’s aphorism can be read as an ethic of intellectual humility. Since simple answers risk deception, we should hold them lightly and watch for counterexamples. Since complex answers risk unusability, we should translate them into testable, revisable heuristics rather than treating them as final. This is why the most reliable thinkers often speak in iterations: a first, usable approximation; then refinements as evidence accumulates. In that ongoing adjustment—never fully satisfied with simplicity, never drowned by complexity—Valéry’s bleak-sounding dilemma turns into a disciplined method for getting closer to truth without losing the ability to act.