Centuries ago, phrenologists studied the conformation of the human skull in an attempt to learn about variation in brain structure and mental function. They viewed the brain as a collection of parts, just as the body can be described as a collection of organs, each with a particular function and a characteristic location. While neuroscientists doubt the details of the phrenological view, the search for the cerebral basis of conceptual knowledge remains a project of functional localization, supported by theories of cognition and behavior. In 1929, it was proposed that brain function depends upon the allocation of fairly homogeneous neural resources to particular tasks. This uniformity of functional capability was called equipotentiality. Extreme localization and equipotentiality lie at two ends of a continuum describing functional organization in the brain.