Do you have to see it to believe it? James Robert Brown, Professor of Philosophy at the University of Toronto, will discuss the highly interesting but controversial topic of the legitimate role of visual thinking in mathematics and science. Examples of picture proofs and thought experiments will be given. An explanation of how they work will be sketched. Proof, pictures, James Brown, axioms, sketches, experiment, Barwise, Godel, isomorphc homomorphic, intuitions, continuum hypothesis, refutation