Passage Summary: A theory only counts as scientific if there is a possible way to prove it wrong through evidence.

Reasoning: The principle establishes that for a theory to be empirical, it must be falsifiable by some imaginable observation.

Analysis: This stimulus provides a conditional rule: if a theory is empirical, then it must be refutable by observation. To justify a conclusion using this principle, we typically look for the 'contrapositive' application: if no observation could ever disprove a theory, then that theory is not empirical. Look for an answer choice that identifies a theory as non-empirical specifically because it is impossible to find evidence that would contradict it. Focus on the requirement of 'conceivable observation' as the gatekeeper for what qualifies as empirical.