Except it isn't that easy to. There is probably going to be some bias, not to mention that subtle unconscious hints from participants could be picked by the par

Except it isn't that easy to. There is probably going to be some bias, not to mention that subtle unconscious hints from participants could be picked by the participants. http://www.newscientist.com/article/dn22144-brain-might-not-stand-in-the-way-of-free-will.html http://www.newscientist.com/article/dn22144-brain-might-not-... Also it's important to remember most of science theories can be overturned easily by new evidence. So I'm not sure science is 100% certain in either way.