Concept · Cognitive Bias: Informal fallacies of ambiguity
Persuasive definition
Origin: Stevenson, 1938
Biological Parallel
Redefining 'invasive species' as 'non-native species that harm ecosystems' smuggles value judgment ('harm') into a descriptive category. This is persuasive definition—loading terms with connotations to win arguments by fiat. But 'harm' is contested: rabbits devastate Australian ecosystems but feed introduced foxes. Who decides harm? The definitional move makes empirical questions look like semantic truths. Biology needs neutral descriptions before normative assessments. Definitions should clarify, not persuade.