What is relative autonomy (Engels), and why does Marxian legal theory need it?

Setting: Florence's diplomat in the age of the Medici, invasion and collapse; The Prince (written1513) — political advice to a new ruler; the Discourses — republican Machiavelli. Both books separate politics from ethics: the founding act of political science as autonomy.The conceptual core:1. Verità effettuale — the "effective truth" study politics as men are, not as they ought to be — against the mirrors-for-princes moralists (the methodological break: descriptive, not normative).2. Virtù vs fortuna:virtù — the skill, vigour and boldness of the statesman; fortuna — chance, the flood that drowns the unprepared (fortune a woman who favours the bold, he notoriously wrote). Statecraft = maximising virtù against fortuna: half our actions governed by fortune, half left to us.3. The lessons of the Prince (statecraft's toolkit): - It is safer to be feared than loved (if you cannot be both) — but never hated (confiscate property sparingly; touch women's honour never); - The prince must learn how not to be good — and use this knowledge according to necessity; - Appearances rule: be fox (recognise traps) and lion (frighten wolves); seem merciful, faithful, religious — seem, since men judge by appearances and the few who know are powerless when the many are deceived; - Arms and laws: good laws from good arms; mercenaries are ruinous — own arms (the national-army principle).…