I haven't read Pascal Pesnsees so I can't speak about that, but I have looked into Plato's allegory of the cave before.

I totally agree with the allegory. But it can use against any kind of argument brought up by anyone.

• If you would say that the Physical world and physical sensations are the only real thing, I can use this allegory against you.
• If you believe in God, I can use the allegory against you.
• If you don't believe in God, I can use the allegory against you.
• If you don't believe in Vampires, I can use the allegory against you.
  So on and so forth.

Anyway, thanks for getting involved in the conversation!