[gaspar]

Rome's Republic was an oligarchy. The Weimar Republic and the thing that passed for a democracy in Italy in the post-WWI period were the stirring of still youthful nation states trying to create something of a congeries of city states, landgraves, principalities, dukedoms, etc.

Generalizations are dangerous, and syllogistically speaking "all" is a dangerous position to take.

[Darth Sidious]

Generalizations are dangerous, and syllogistically speaking "all" is a dangerous position to take

Except generally speaking, it is an observation that has held true 100% of the time over history.

Try as one might, there cannot be found any republic/democracy that has made it past, on average, two hundred years, and still maintained its principles. All of them deteriorated into either tyranny or stagnancy.