the data part of a course, where data as in books, tapes and manuals is given. See also practical.the principles or methods of a science or art rather than its practice. I couldn't understand exactly what it was all about because he knew absolutely nothing about technology, theory, he knew nothing about nomenclature. -How We Have Addressed the Problem of the Mind (4 July 1957)the part of a course where one learns by studying written materials.that branch of an art or science dealing with knowledge of its principles and methods rather than with its practice.that branch of an art or science dealing with knowledge of its principles and methods rather than with its practice. See also science in this glossary.the principles or methods of a science or art rather than its practice.