It is unnecessary to deal specially with each of the many writers who have used from different stand-points the _à posteriori_ form of argument in order to prove the existence of Deity. The objections already stated apply to the whole class; and, although probably each illustration used by the Theistic advocate is capable of an elucidation entirely at variance with his argument, the main features of objection are the same. The argument _à posteriori_ is a method of proof in which the premises are composed of some position of existing facts, and the conclusion asserts a position antecedent to those facts. The argument is from given effects to their causes. It is one form of this argument which asserts that a man has a moral nature, and from this seeks to deduce the existence of a moral governor. This form has the disadvantage that its premises are illusory. In alleging a moral nature for man, the Theist overlooks the fact that the moral nature of man differs somewhat in each individual, differs considerably in each nation, and differs entirely in some peoples. It is dependent on organisation and education; these are influenced by climate, food, and mode of life. If the argument from man’s nature could demonstrate anything, it would prove a murdering God for the murderer, a lascivious God for the licentious man, a dishonest God for the thief, and so through the various phases of human inclination. The _à priori_ arguments are methods of proof in which the matter of the premises exists in the order of conception antecedently to that of the conclusion. The argument is from cause to effect. Amongst the prominent Theistic advocates relying upon the _a priori_ argument in England are Dr. Samuel Clarke, the Rev. Moses Lowman, and William Gillespie. An important contribution to Theistic literature has been the publication of the Baird lectures on Theism. The lectures are by Professor Flint, who asks: “Have we sufficient evidence for thinking that there is a self-existent, eternal being, infinite in power and wisdom, and perfect in holiness and goodness, the Maker of heaven and earth?”