Phrenology (from Greek φρήν (phrēn), meaning "mind", and λόγος (logos), meaning "knowledge") is a pseudoscience primarily focused on measurements of the human skull, based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions  or modules. Although both of those ideas have a basis in reality, phrenology extrapolated beyond empirical knowledge in a way that departed from science