created the symbols for the printing of the book. Wilkins's "Real Character" is a constructed family of symbols, corresponding to a
classification scheme developed by Wilkins and his colleagues. It was intended as a
pasigraphy, in other words, to provide elementary building blocks from which could be constructed the universe's every possible thing and notion. The Real Character is not an
orthography: i.e. it is not a written representation of
spoken language. Instead, each symbol represents a concept directly, without (at least in the early parts of the ''Essay's'' presentation) there being any way of vocalizing it. Inspiration for this approach came in part from contemporary European accounts of the
Chinese writing system, which were somewhat mistaken. Later in the
Essay Wilkins introduces his "Philosophical Language", which assigns phonetic values to the Real Characters. For convenience, the following discussion blurs the distinction between Wilkins's Character and his Language. Concepts are divided into forty main
Genera, each of which gives the first two-letter syllable of the word; a Genus is divided into
Differences, each of which adds another letter; and Differences are divided into
Species, which add a fourth letter. For instance,
Zi identifies the Genus of "beasts" (mammals);
Zit gives the Difference of "rapacious beasts of the dog kind";
Zitα gives the Species of dogs. (Sometimes the first letter indicates a supercategory—e.g. Z always indicates an animal—but this does not always hold.) The resulting Character, and its vocalization, for a given concept thus captures, to some extent, the concept's
semantics. The
Essay also proposed ideas on weights and measure similar to those later found in the
metric system. The botanical section of the essay was contributed by
John Ray;
Robert Morison's criticism of Ray's work began a prolonged dispute between the two men. ==Related efforts, discussions, and literary references==