εἰ δὲ ζήτημά ἐστιν περὶ λόγου καὶ ὀνομάτων καὶ νόμου τοῦ καθ᾽ ὑμᾶς ὄψεσθε αὐτοί· κριτὴς γὰρ ἐγὼ τούτων οὐ βούλομαι εἶναι
Acts 18:15
If the controversy has to do with the words and names and law of your own, see to it yourself. I do not wish to be a judge of such matters.
The law ineluctably has to do with language. The modern word 'law' traces from the Old French 'ley,' which has the same sense as the poetic ley. It is a word remembered that helps us to judge the event. When we find the dead body in the library with Col. Mustard holding a bloody lead pipe standing over it, in order to judge the event, we consider whether we would use the word murder to apply to the event, or perhaps manslaughter or misadventure. So perhaps Gallio doesn't get off as easily as he does in the usual translations -- it isn't that the matter is merely about words, but it is about the words of a certain people, the diaspora Jews.
Wilde, on trial in England, was questioned as to whether a certain expression was blasphemous. He replied something along the lines of "I have no idea -- blasphemy is not one of my words." If someone speaks falsely about an important thing, perhaps there are two risks. The first is empirical--something might be done badly, the wrong button might be pushed, a nation might go to war, someone might go without dinner. The second, nonpragmatic and nonpragmaticist danger is that the speech held to be false might confound the reticulated structures of belief and understanding within people. If someone in a position of authority teaches that God is merely a harmless delusion of the past, everything in society will keep chugging along, and while there may be some incidental effects, such as a lack of Sunday church attendance, but that is not the meaning of the event. Each time God is referred to, the reference is shortchanged, and dismissed in the mind. The world becomes a dull, pragmatic affair in which we are to do the expected actions, and then die and be buried by our kin. I suppose you could say that the consequence of the changed belief is another belief, but this second belief also has a qualitative aspect in being more circumscribed, and bearing relation to fewer things. The world of our ideas can be either lively or dim, and the difference is merely an idea.
Gallio's expression is interesting. He doesn't use the strong form of decision and speak of will. Instead, he uses a word corresponding more closely to 'wish,' as if he were a Homeric god looking down on the matter from Olympus. Now, a diligent and empirical fellow with general jurisdiction over the cases and controversies arising within his area of control might seek to keep the peace (note the locals' subsequent attempt to create a genuine matter in controversy by beating up a synagogue official), despite the risk of entanglement in religious questions. Religious questions, at the time, stood proxy for matters of ethnic law and order -- each people had their god, and the ways in which they spoke of their god often had very much to do with the character of the people. Gallio's abstention is prudential, apparently not compelled by his own law. In matters between nations, perhaps there is no guide in our own law or custom as to how to interfere in another's law. To do so is not a crime, but a mistake. So to stand between nations, or perhaps between groups of people using different words to describe the world, one has to have a robust personal sense of right and wrong, and right words of one's own at the ready.