What developed after the English Civil War to express political beliefs?

Answer 1

A popular answer is to say that political parties were organized forms of political expression that grew out of the unorganized factionalism of the Restoration-era English Parliament, and that (in an extremely loose sense) the rivalries of the Whigs and Tories were sublimated continuations of the deep religious and philosophical divides between the Roundheads and the Cavaliers. But this presupposes that a political party is somehow functionally distinguishable from a less formally organized group of like-minded people, or that no such thing as a named, self-perpetuating political faction existed anywhere in the world prior to the English Civil War.

The Greek schools of philosophy; the plebian organizations of Republican Rome; the internecine factions of the early Catholic church; the persistent, multi-generational group-political rivalries of the Renaissance Italian city-states; what distinguishes political parties as institutions from any of these entities? If there is any distinction, it is only by degrees of administrative sophistication.