I’m only in the middle of the introduction, but it appears the primary thesis of Harold Berman’s “Law and Revolution” is that the development of papal law & ecclesiastical autonomy represented a radical break with the past that defined the “modern” era (which he defines as taking place from about 1050 AD until 1945). He acknowledges that there was also more gradual evolution interacting with his specified periods of revolution (in addition to the usual ones he refers to the reformation as the “German Revolution”) we can also detect more extreme discontinuities in the law (which has always served a role of transmitting tradition). For instance “One cannot say, for example, that trial by ordeal and trial by battle gave rise to trial by jury […]”. Perhaps not trial by jury itself, but allegedly there is a hallowed feature derived from trial by combat: the right to confront one’s accusers. At least that’s the basis of this feminist argument that the right should be “unincorporated” for cases of domestic violence. Since I never bought into incorporation, I agree, though I don’t know what the state constitutions say. Peter Leeson argues that trial by battle was an efficient means of solving the disputes faced by courts of that time.