From The Art and Popular Culture Encyclopedia
Sui generis is a Latin expression, literally meaning of its own kind/genus or unique in its characteristics. The expression was created to indicate an idea, an entity or a reality that cannot be included in a wider concept. In the structure "genus → species" a species that heads its own genus is sui generis. The word is pronounced SOO-eye jen-ER-ihs. A modern day equivalent is the phrase genre-defying.
The term is widely used to refer to more esoteric entities in a number of disciplines, including
- philosophy, when a concept is not available;
- biology, when a species does not fit into a genus which includes other species;
- law, when a special and unique interpretation of a case or authority is found to be necessary;
- intellectual property rights, where there is no defining characteristic; and
- politics and societal norms, where there is no real authority perceived.
- creative arts, where an artistic work goes beyond conventional genre boundaries.
In the taxonomical structure "genus → species", a species is described as sui generis if its genus was created to classify it (i.e., its uniqueness at the time of classification merited the creation of a new genus, the sole member of which was initially the sui generis species). A species that is the sole extant member of its genus (e.g. the Homo genus) is not necessarily sui generis: extinction may have eliminated other species of that genus.
A book, movie, television series, or other artistic creation is said to be sui generis when it does not fit into standard genre boundaries. Movie critic John Shanley identifies Joe Versus the Volcano as a sui generis movie. Much of Joss Whedon's work is also sui generis, to the point where his name has become adjectival in describing his work. The video game Killer7 is often referred to as a game without genre, due to its combination of on-rails movement, first-person aiming and puzzle solving.