 Contrary to what has sometimes been feared, the broad grouping of mental disorders does not require an embrace of unwanted metaphysical dualism. Mental disorders are conditions or states attributed to persons, but this need entail neither that they are entirely non-physical in nature, nor that they must be explained in solely neuro-scientific terms. Maintaining the separation between mental and physical disorders is compatible with some form of weak physicalism, for example, allowing that mental or psychological processing involved in functions such as perception, reasoning and memory, depends on the workings of the brain (see Schaffner 2013 and the  entry on health).