  Still, for those (including Huxley) who became quickly convinced of the correctness of Darwin's theory of evolution, understanding and defending mental continuity between humans and animals loomed large. In his Principles of Psychology (1890), William James promoted the idea of differing intensities of conscious experience across the animal kingdom, an idea that was echoed by the leading British psychologist of his day, Conwy Lloyd Morgan in his 1894 textbook An Introduction to Comparative Psychology. Morgan had been very skeptical and critical of the anecdotal approach favored by Darwin and Romanes, but he came around to the Darwinian point of view about mental continuity if not about methodology.  To address the methodological deficit he introduced his “double inductive” method for understanding the mental states of animals (Morgan 1894). The double induction consisted of inductive inferences based on observation of animal behavior combined with introspective knowledge of our own minds. At the same time, to counteract the anthropomorphic bias in the double inductive method, Lloyd Morgan introduced a principle now known as Morgan's canon: “in no case may we interpret an action as the outcome of the exercise of a higher psychical faculty, if it can be interpreted as the outcome of the exercise of one which stands lower in the psychological scale” (Lloyd Morgan 1894, p.53).