Visesha is a category in Vaisheshika philosophy. Visesha, meaning particular, is one of the seven categories, or saptapadarthas. It is a counterpart of samanya, which means ‘general’, and one necessarily implies the presence of the other. Visesha is defined as residing in eternal substances for the purpose of distinguishing them from one another, and they are innumerable, one being assigned to each eternal substance. A more accurate definition is ‘that which distinguishes self from itself.’
The eternal substances in which viseshas in here are the atoms of the first four substances, namely, earth, water, light, and air, together with the remaining eternal substances of ether, time, space, self and mind.
Other definitions of visesha also convey that visesha is a category (padartha) assumed to account for the differences of atoms and other eternal substances from one another. The necessity for such an assumption is established as a jar is distinguished from a piece of cloth, because the component parts of the former are distinct from those of the latter (avayavabhedat avayavibhedah) and so on. Finally we arrive at the ultimate constituents of matter, namely, the atoms. However, since an atom has no parts, it is not possible to account for the distinction between one atom and another by the same process of reasoning. Similarly, we cannot account for the mutual distinction of the imperishable substances such as ether, time and space. It is, therefore, assumed that there is separate individuality in each of the substances which accounts for its distinctive character. This individuality is called the visesha of that substance and the substances are as innumerable as the atoms and other eternal substances.
This doctrine of visesha is a peculiar tenet formulated by the Vaiseshikas, who have acquired their appellation from the name of the doctrine. Kanada, while treating samanya, distinguishes its occasional viseshatva from the well-known ultimate viseshas that are called final, because they reside in the final atoms of matter.
Other schools of Indian philosophy, such as the Mimamsakas, Vedantins, etc., do not accept the doctrine of Visesha.