If the Jacobins weren't Utopian, what were they? A party which introduces an entirely new dating system clearly thinks of itself as a new order. And while the British beheaded a king, the French beheaded the King, his wife, his sister, old men, old women, children, nuns, priests and women, to say nothing of abusing the ten year-old Dauphin to death (my namesake). And yeah, sure, the French Revolution didn't start out to be what it became, but it devolved pretty quickly --- they were brutally murdering people on the very first day, and when the mob hit Versailles in October, 1789, they were fairly awful. And after a respite (of sorts), they were worse than awful in the September Massacres. I think Thatcher is right on the money in her comparison with the Bolsheviks, who after all murdered millions (better equipment, not more zeal). And the reason everyone gets exercised about the events of July, 1918, is that it is emblematic of the Bolshevik mentality --- you can make some sort of argument for Nicholas' execution, although to give the French and British their due, they at least put Louis XVI and Charles I on trial before they killed them --- but what possible legal justification could there be for the execution of the five children, to say nothing of the hapless servants. We even refer to the period that followed as "the Terror". And yes, of course, the French Revolution had stages, but Thatcher is right on the money in terms of what people mostly remember about the event: ask people to describe the French Revolution, and they don't start talking about the Estates General or the Directory, anymore than when we talk about the Third Reich we focus upon the regime's agricultural achievements.
I think you are on the money, Tsarfan, in crediting human rights to the Greeks (with the normal historical provisos, Greek democracy being limited). Perhaps the value that Christianity adds to the discussion is that it imputes value to each individual life because he/she has an immortal soul. While not very comforting to the heretic being executed, it is possible to maintain that the Inquisitors operated on the assumption that they were doing both the victim and society a favor by either saving his soul, or preventing the contamination of others' souls and thereby saving them from eternal damnation. Yes, it's a grotesque idea in the 21st century, but we've only been in it for twelve years.