Intellectual capacity is the ability to think, reason, and understand concepts. It is often referred to as mental or cognitive ability. The term can be broken down into three words: BRAIN (5 letters), MIND (4 letters), and BRAINPOWER (10 letters). BRAIN is the physical organ that controls thought processes, while MIND is the mental faculty that enables us to think, reason, and remember. BRAINPOWER is the combination of both BRAIN and MIND, and is the capacity to use one's intellect to solve problems.