Wycliffism and Lollardy raise a question of fundamental relevance to the study of late-medieval 'heresy' in England. This chapter explores whether it might be meaningful to use 'Wycliffism' and 'Lollardy' at least for purposes of analysis as designating conceptually distinct phenomena, whatever their actual interrelationship may have been in late-medieval England. The episcopal condemnation in 1277 of 219 Aristotelian articles allegedly supported by members of the faculty of arts in the University of Paris had a long prehistory and an equally substantial posterity. The implied endorsement of lay, extra-institutional, spiritual authority was sometimes accompanied by a questioning of the efficacy and administration of the sacraments. Of equal importance in Wyclif's polemic is anticlericalism. Wyclif's work both uses and critiques the academic-rationalist tools available to medieval scholasticism. Alexander Patschovsky's insight can be of assistance in broaching the vexed question of the medieval meanings and definitions of 'heresy' in general, and of Wycliffism/Lollardy in particular.