For some reason, today it became important to know when silent reading developed. In the middle ages, and in antiquity, the custom was to always read aloud. Monastic libraries would be full of mutterings and it must have been impossible to read private letters in public.

Then i found this essay and everything started to go ‘zing!’ inside my head. Seems the diffusion of the custom of word spacing (strange to think that something as unconscious as putting spaces between words needed invention. Strangetothinkthatsomethingasunconsciousasputtingspacesbetweenwordsneededinvention) was instrumental in allowing the development of silent copying and silent reading.

And- fantastic!- you can trace the historical development of this by looking at changes in the rules of monastic orders:

Reading likewise became a silent activity, as evidenced by changing interpretation of the rule of silence. Before about the 10th century, “oral group reading and composition [were] in practice no more considered a breach of silence than were confession or the recitation of prayers. Cluniac monks were judged to have violated their vows of silence only when a word they spoke was not written in the text.” (383) But later, “silence” comes to mean real silence.

So The Word is on a historical trajectory from phonetic to visual unit (Remember Neal Stephenson’s In the Beginning was the command line. Notice Jocelyn Penny Small’s essay on Psycoloquy)

And, again from Relevant History, silent reading lets us interact with the written word in new ways

Books that were meant to be read silently differed from those meant to be read aloud: they were more visually complex, and their design could incorporate metadata and visual cross-references that wouldn’t make sense in books that were read aloud. What other scholars have referred to as paratexts– .e.g, “tables of contents, alphabetical glosses, subject indexes, running headings” (408)– only really work in books that you interact with visually rather than orally.

All these changes, marking “the transformation from an oral monastic culture to a visual scholastic one between the end of the 12th and the beginning of the 14th centuries” (405) are first confined to the ecclesiastical worlds, but from the 14th century they spread in lay literate culture.

And then silent reading changes the nature of self-consciousness, another part in the development of the primacy of individual perspective. Is it coincidence that the widespread adoption of silent reading is coincident with the beginning of what we know of as the Modern period?

…private reading becomes a space for “individual critical thinking” that encourages “the development of skepticism and intellectual heresy.” (399) Likewise, spiritual literature in the 14th century was meant to be read alone, turning reading itself into a kind of meditation (that incidentally involved the highest of the senses, sight).
The privacy afforded by silent reading had the same effects in lay society that it did in scholastic circles. It made easier the cultivation of individual opinions and subversive thoughts…It also made religious feeling into a more private matter.