38. But when all these have been cut away and rooted out of the mind of the Christian, we must then look at human institutions which are not superstitious, that is, such as are not set up in association with devils, but by men in association with one another. For all arrangements that are in force among men, because they have agreed among themselves that they should be in force, are human institutions; and of these, some are matters of superfluity and luxury, some of convenience and necessity. For if those signs which the actors make in dancing were of force by nature, and not by the arrangement and agreement of men, the public crier would not in former times have announced to the people of Carthage, while the pantomime was dancing, what it was he meant to express, -- a thing still remembered by many old men from whom we have frequently heard it. And we may well believe this, because even now, if any one who is unaccustomed to such follies goes into the theatre, unless some one tells him what these movements mean, he will give his whole attention to them in vain. Yet all men aim at a certain degree of likeness in their choice of signs, that the signs may as far as possible be like the things they signify. But because one thing may resemble another in many ways, such signs are not always of the same significance among men, except when they have mutually agreed upon them.