Scribes in the remote past had one hell of a job: preserving oral events into a permanent record of history, usually in cultural environments where they were the only literate individuals for hundreds of miles in all directions. It is no surprise that they made mistakes from time to time, and that these mistakes survived to be read by modern readers, especially in religious texts, which usually pass through multiple translations and transcriptions over thousands of years. The following is a non-exhaustive list of several types of scribal errors.

Ancient Errors (pre-Gutenberg):

a. Unintentional errors:

1. Errors of vision:

Scribes often worked in a scriptorium with poor lighting, or lighting dependent on the time of day. Old age and the lack of eyeglasses also had an influence on the work of scribes. This led to errors like the following:

i. Mistaking one symbol for another, e.g. 0, 8, θ, Q, and O

ii. Parablepsis 1 (lit., looking by the side): Omitting passages lying between lines that end with the same letters, words, or phrase (homeoteleuton), or haplography like writing philogy for philology.

iii. Parablepsis 2: Duplicating passages that end with the same word or phrase (dittography). This error and the one previous are usually made when scanning passages horizontally, but they occur less often in boustrophedon writing than in writing which always scans only left-to-right or right-to-left.

iv. Vertical scanning errors: Omitting or duplicating passages (or even pages) beginning with the same word or phrase, an error usually made when scanning texts from top to bottom.

v. Bookbinding errors: When a bookbinder transposes pages that begin with the same word or phrase (or even the same initial letter, in heavily illuminated texts.

2. Errors of hearing:

i. Homophony: the difference between "there," "they're," and "there."

ii. Itacism: Greek vowels like η, ι, υ and diphthongs like ει, οι, and υι all came to be pronounced similarly, like 'ee' in feet. One vowel or diphthong might replace another, changing the meaning of the word.

iii. Accent, tone, and breath errors: Tonal languages may differentiate half a dozen different words based on how vocal pitch shifts. Many languages rely on syllable weight, stress, accent, and vowel length to differentiate words. Ancient Greek words can be pronounced with rough or smooth breathing, and these have distinctive accent marks. If a scribe misheard any of these differences, they would write the wrong symbol and therefore the wrong word.

iv. Similar-sounding consonants could be mixed up, like κ and ξ, or p and b.

v. Single consonants like λ or L could be mistaken for double consonants like λλ and Ll, and vice versa.

3. Mnemonic errors:

Most of us have done this one - holding a word or phrase in mind, or seeing one written somewhere nearby, and writing that instead of what we intend to write.

i. Synonyms: words of related meanings in one language could be interchanged, resulting in very different translations at later times.

ii. Letter sequences: Individual letters within words could be interchanged, like ελαβον (receive) or εβαλον (thrust away).

iii. Word sequences: Phrases like 'Jesus Christ' or 'Christ Jesus' are commonly swapped for each other.

iv. Familiar passages: Sometimes, scribes would substitute or add passages with which they were more familiar (or may have learned by heart) for the actual passage, especially those that dealt with the same subject.

4. Errors of judgment:

i. Extrabiblical words: Marginal notes, headings, and other notation from earlier editors were sometimes incorporated into the text.

ii. Linguistic ignorance: Since many scribes could not actually read Hebrew, Greek, or Latin but were mechanically copying what they saw, numerous errors have crept into the text.

iii. Mistaking letters for numbers and vice versa: After the 2nd century CE, letters of the Greek alphabet also served as numerals, leaving ample room for errors, e.g. ά = 1, β' = 2, ί = 10, ρ' = 100, etc.

iv. Errors of spacing: Many early manuscripts were written with no space in between letters or words. Later scribes sometimes made arbitrary splits between letters and words, often changing the meaning of the text, e.g. “godisnowhere” might be read "god is nowhere" or "god is now here."

b. Deliberate errors:

Some passages of writing were changed intentionally to serve a specific purpose. Jehovah's Witnesses do not believe in the full deity of Jesus Christ, so in John 1:1, they render “The Word was God” as “The Word was a god.”

Modern Errors (post-Gutenberg):

All of the above categories continue in modern times, with the added bonus that countless copies can be made featuring the same error, instead of just one copy at a time produced by hand. The Wicked Bible, published in London in 1631, deleted the “not” in Exodus 20:14, causing it to say “Thou shalt commit adultery.”

Iron Noder 2016, 20/30