A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.

Noteworthy treatises

Treatises have been written by various philosophers:

Treatise is a musical composition by British composer Cornelius Cardew (1936-1981). Treatise is a graphic musical score comprising 193 pages of lines, symbols, and various geometric or abstract shapes that eschew conventional musical notation. Implicit in the title is a reference to the philosophy of Ludwig Wittgenstein, which was of particular inspiration to Cardew in composing the work. The score neither contains nor is accompanied by any explicit instruction to the performers in how to perform the work. Cardew worked on the composition from 1963 to 1967.

Although the score allows for absolute interpretive freedom (no one interpretation will sound like another), the work is not normally played spontaneously, as Cardew had previously suggested that performers devise in advance their own rules and methods for interpreting and performing the work. There are, however, almost infinite possibilities for the interpretation of Treatise that fall within the implications of the piece and general principles of experimental music performance in the late 1960s, including presentation as visual art and map-reading (Anderson 2006).