Precautionary Principle

The principle that when an action carries the potential for SEVERE, IRREVERSIBLE harm, the burden of proof falls on those proposing the action to demonstrate SAFETY—rather than on opponents to demonstrate danger. Applied to environmental policy, public health, AI safety, and any domain where potential harms are catastrophic and hard to reverse. The asymmetry: if you're wrong about safety and proceed, the harm may be irreversible. If you're wrong about danger and pause, the cost is delay. As a mental model: precaution applies specifically to ASYMMETRIC risk situations where the cost of being wrong in one direction vastly exceeds the cost of being wrong in the other direction.

When to use it

When potential harms are severe and irreversible; when the cost of being wrong about safety vastly exceeds the cost of delay; when burden of proof needs to be placed on those proposing risky action; when distinguishing between ordinary risk (accept and manage) and catastrophic risk (precaution required).

How it can help

Apply the precautionary principle where risks are asymmetric: potential harms are severe and irreversible, while the cost of caution is delay or lost opportunity. The practice: (1) Assess ASYMMETRY: is the downside catastrophic and irreversible? Is the upside incrementally beneficial? If yes: precaution is warranted. (2) Place the BURDEN OF PROOF on the proposer of action to demonstrate safety, not on the objector to demonstrate danger. (3) Invest in RESEARCH to reduce uncertainty before committing. (4) Design REVERSIBLE first steps. For entrepreneurs: the precautionary principle applies to decisions affecting customer safety, data privacy, and regulatory compliance—not to ordinary business risks.