Living complex biological system which functions as a stable whole. In contrast to colonial organisms their components generally cannot survive on their own. We conceive organisms in a material sense. Therefore we do not assume any ontological difference between a unicellular organism and the cell it is made of. "Colonial Organism" are not considered Organisms. We here include viruses into the category of organisms. Organism in an inactive form which are not dead are considered living organisms. Whether a living organism coincides with its body or hasPart its body, is controversial. We use "hasPhysicalPart" for relating organism to body. Being reflexive, this would not be incompatible with a view in which a living organism is a body.