Inconsistency reveals fault lines in a coherent system. True systems like mathematics and physics have no internal contradictions. No law about addition or subtraction contradicts any other law about multiplication or division. No law about gravity or optics contradicts another law about motion or electricity. Yet, repeatedly, the system known variously as liberalism/leftism/progressivism/secular fundamentalism/socialism reveals internal contradictions. It is clear that it is no coherent system.