I imagine that whenever the mind perceives a mathematical idea, it makes contact with Plato's world of mathematical concepts... When mathematicians communicate, this is made possible by each one having a direct route to truth, the consciousness of each being in a position to perceive mathematical truths directly, through the process of 'seeing'.

The Emperor's New Mind: Concerning Computers, Minds, and the Laws of Physics (ed. OUP Oxford, 1999) - ISBN: 9780191506413