Philosophy ceases to be philosophy when its claims can be tested empirically. The major branches of science (physics, chemistry, biology, astronomy, etc.) were once considered topics in philosophy, but are no longer. It appears that Philosophy of Mind is currently making this transition.
(Edit: Changed "Theory of Mind" to "Philosophy of Mind"... psychology lingo crept in there for a second)
Absolutely true, however it's a bit overzealous to jump from starting to understand how the brain works to materialistic assumptions about the nature of consciousness of free will.
(Edit: Changed "Theory of Mind" to "Philosophy of Mind"... psychology lingo crept in there for a second)