The major trends of philosophy of the past hundred years in both the English and the German speaking world have derived directly or indirectly from recoil against the British school of thought which began with Locke and culminated in John Stuart Mill. Subsequent theories of knowledge, perception, deduction, induction, probability, mathematics and semantics (not to speak of ethics, politics and political economy) can nearly all be traced back to revolts against the conclusions and the premisses of this school. In particular Mill’s System of Logic (1843) stimulated (chiefly as an emetic) a galaxy of original thinkers into reconsideration of the principles of logic, epistemology and psychology.