genus, summum See GENUS GENERALISSIMUM. genus generalissimum (Latin, ‘most general genus’), a genus that is not a species of some higher genus; a broadest natural kind. One of the ten Aristotelian categories, it is also called summum genus (highest genus). For Aristotle and many of his followers, the ten categories are not species of some higher all-inclusive genus – say, being. Otherwise, that all-inclusive genus would wholly include its differences, and would be universally predicable of them. But no genus is predicable of its differences in this manner. Few authors explained this reasoning clearly, but some pointed out that if the difference ‘rational’ just meant ‘rational animal’, then to define ‘man’ as ‘rational animal’ would be to define him as ‘rational animal animal’, which is ill formed. So too generally: no genus can include its differences in this way. Thus there is no all-inclusive genus; the ten categories are the most general genera. See also DEFINITION , PRAEDICA – MENTA , PREDICABLE. P.V.S.