  Critics have found many of these principles questionable and their status as self-evident more questionable. Some critics have argued that they are poorly articulated since Reid does not state definitions of key terms like “intention of nature.” Others argue that they depend upon the truth of Christianity. For example, Reid's defense of his second Principle 2 includes discussion of the way in which God has “excellently fitted” our conscience, reason, natural instincts and bodily appetites to the benefit of the species.