[rubecube]

Originally Posted by CorsiHockeyLeague

Ah, I see. Good question, and probably no easy answer aside from the classic pornography one - you know it when you see it. If someone consistently makes arguments rooted in liberal principles, and you can draw a clear line from those principles to their behaviour, it's probably fair to call that person a "liberal" in general. If someone consistently shirks liberal principles, and their behaviour rarely matches up with what you'd expect to see someone following liberal principles doing (even if they might sometimes by sheer coincidence), they probably aren't.

Where to draw the line exactly, I can't really tell you, but as a practical shorthand that process works for me. If I'm paying attention to someone's public positions, patterns usually emerge, and you tend to notice anomalies in behaviour. If, for example, Clifffletcher tomorrow posts in support of a new bill banning people from criticizing others' religious beliefs in public, for example, I'm going to be surprised. If Mike Pence tweets his support, meanwhile, I won't be quite so shocked.

Sorry, I should have clarified. My question was more along the line of how you come to a consensus on the epistemicological foundation of liberal principles. With Marxism it's fairly easy because you can just consult Marx. Who do we agree is the authority on what the tenets of liberalism are?