We have a brain for one reason and one reason only — and that’s to produce adaptable and complex movements.

Source:

"The Real Reason for Brains." TEDGlobal 2011. Jul. 2011. Conference Presentation.

Additional Information: This quote is from neuroscientist Daniel Wolpert's 2011 TED Talk. The quote describes the main point discussed in this Talk: that the human brain exists primarily to control the body's movements, not to think or perceive. Watch the full TED Talk here: Daniel Wolpert - The Real Reason for Brains