Book III, Chapter V

They draw another argument from the text of Moses, saying that the types of these two powers sprang from the loins of Jacob, for that they are prefigured in Levi and Judah, whereof one was founder of the spiritual power, and the other of the temporal. From this they argue: the Church has the same relation to the Empire that Levi had to Judah. Levi preceded Judah in his birth, therefore the Church precedes the Empire in authority.

This error is easily overthrown. For when they say that Levi and Judah, the sons of Jacob, are the types of spiritual and temporal power, I could show this argument, too, to be wholly false; but I will grant it to be true. Then they infer, as Levi came first in birth, so does the Church come first in authority. But, as in the previous argument, the predicates of the conclusion and of the major premiss are different: authority and birth are different things, both in their subject and in their idea; and therefore there is an error in the form of the argument. The argument is as follows: A precedes B in C; D and E stand in the same relation as A and B; therefore D precedes E in F. But then F and C are different things. And if it is objected that F follows from C, that is, authority from priority of birth, and that the effect is properly substituted for the cause, as if "animal" were used in an argument for men, the objection is bad. For there are many men, who were born before others, who not only do not precede those others in authority, but even come after them: as is plain where we find a bishop younger than his archpresbyters. Therefore their objection appears to err in that it assumes as a cause that which is none.