Fridays are for rhetoric! I remember when I first encountered teachers who were trying to experiment with interdisciplinary study units. For some reason, this idea, which has been around naturally since the beginning of time, got lost in the specialized educational plans of the 20th century. Some brave souls started to recapture it late in the century. Quintilian says you can, no, must, pull various disciplines together. Otherwise the student will be unbalanced.
Quintilian, and J.S. Watson. Institutes of Oratory.Edited by Lee Honeycutt, 2010. Kindle Electronic Edition. Book I Chapter 10
Having discussed the necessary elements of grammar and style, Quintilian turns his attention to other areas which deserve study as boys prepare to work with a rhetorician. Reminding the reader that he is describing the ideal training of an orator (Quintilian I.10.4) he resists claims of others that a broad education is unnecessary for an orator. “Shall we wonder that eloquence, nothing more excellent than which the providence of the gods has given to men, requires the aid of many arts, which, even though they may not appear or put themselves forward in the course of a speech, yet contribute to it a secret power and are silently felt?” (Ibid., I.10.7). Quintilian discusses the positive historic link between music and literature at some length. In section 22 Quintilian concludes that both the use of the voice and of gesture, which normally accompanies music, are of importance to the orator. He then goes on to describe the way an orator uses voice and gesture musically to move affections. In section 34 Quintilian begins to discuss geometry and its relation to oratory. Not only is it useful as a mental exercise but also because knowledge of figures is necessary in many situations. Fluency with numbers is therefore important (Ibid., I.10.35). Additionally, geometry deals with orderly arrangement, which is essential to the work of an orator.