Joined Feb 2017
144 Posts | 16+
Pacific Ocean
And how did Hitler, Stalin, etc, manage to stay in power without currying the favour of the mailmen and tax collectors? The fact you compared the Roman Senate to tax collectors is itself the end of the argument. You need some supporters obviously, and you can't displease 100% of people in society, but that's in no way the same thing as suggesting the Senate had some kind of leverage over Augustus. If they didn't like him he had all the leverage he needed; it's called an army. That's why often the Senate didn't support emperors, and it didn't matter one bit (because the Emperor had the army behind him, like in the case of Vespasian, Caracalla or Septimius).
It's also silly to talk of the possibility of assassination as demonstrating some kind of power sharing, because any dictator has his power hedged by practical considerations of some kind of another. You don't need to be literally invulnerable to overthrow to be a dictator. In the case of Augustus specifically, which is who you seem to be focusing your arguments on (and ceding the later emperors totally), I think you'd still be hard pressed to make the argument stick. If he'd been assassinated after assuming sole power his adherents (or just people who wanted to fill the power vacuum and legitimize themselves) would immediately have used the army to destroy his killers and become the new emperors (independent of the Senate). The armies would never have stood for his assassination and the resumption of Senate rule, his support there was too strong (something many later emperors lacked). The common people wouldn't have stood for it either (again, something not true of all later emperors).
Because Hitler and Stalin, as all dictators, didn't need to be on good favors with mailmen and tax collectors per se, but only to their direct subordinates, which had direct subordinates to them, and so on, until you get to the mailmen and tax collectors. If it helps, you could call them "Grand Tax Collectors" or "Masters of Mail", but the fact is that the Senate had indeed an administrative role, which included not only tax collection but also military roles and others. I would appreciate if you tried not to create straw men out of my arguments.
I was focusing my arguments on Augustus because it doesn't seem to make sense to focus them on later emperors. The failed attempt of the Senate to re-create the Republic after the death of Caligula makes that obvious — the Praetorian Guard simply ignored them and named another emperor, and some of the senators even gave speeches while still wearing their rings with Caligula's face on them, which is a clear sign that they had no idea what a Republic was and how it was supposed to work.
But while Augustus ruled, specially in the beginning of his rule, senatorial revolts aiming at the return of the Republic seemed possible, because the Senate still had at least constitutional power to do so and there were still people alive that remembered that period of Rome's history. That is why Augustus went to great lengths to hide his power constitutionally, using auctoritas instead of imperium, even if eventually he secured them to his successors. Also, it would be impossible to maintain the army under his command if Augustus didn't make reforms that limited time of service and created a system of state-paid salary.
An example of how Augustus feared the Senate and its retaliations is that their word was now turned into law, whereas before it was merely a show of auctoritas, technically not an order to be obeyed. I think people argue that his power was shared with the Senate because of this, because not only his pronouncements had power of law but also the Senate's.
But I see your point and am inclined to reassess my position. Even if Augustus needed the illusion that his power was shared, in an unspoken level it indeed wasn't. I confused the fact that he needed to hide his power, at least initially, with the existence of real power by the Senate. In retrospect, a silly mistake. I also agree with you that his assassination would not result at the resumption of Senate rule, even if they could still think that it would, like they thought it while killing Augustus' adoptive father.