 One reason for the invitation to doubt extended by Neo-Confucians seems to have been their realization that many Neo-Confucian tenets, especially metaphysical ones, were profoundly novel. Upon first hearing these new ideas, students might have many questions before they could accept them. So, the Neo-Confucians typically encouraged students to ask questions and reflect critically on the matters prompting their doubts. By doing so, the critical spirit so often associated with philosophy as a discipline in the West was clearly instilled in the early-modern students of Neo-Confucian thought. There can be little question that the number of extended critiques of Neo-Confucian thinking in the early-modern period were in part an outgrowth of the invitation to doubt advocated by proponents of Neo-Confucianism. Far from a rigid and unchanging orthodoxy that allowed for little if any questioning and doubt, Neo-Confucianism actively engaged doubt as a prerequisite to progress in learning.