For those that could read, what punctuation there was, up until the 17th century, was used exclusively for pacing oratory. Should you ever riff through your Shakespeare, use these marks as your guide as you orate. Beyond allowing actors an infusion of oxygen, it also allowed for clarity in the written language though use of punctuation to demarcate important stops, detours and reroutings of thought.
Literary immortality is a strange and fickle mistress.
But you take immortality where you may. Indeed, how one uses punctuation is often as indentifiable a mark of a writer's personal style as how he or she strings his words together. This is not to say punctuation has been set in stone since the 17th century. In the 18th century, for example, every subordinate clause, and separable phrase, was separated by a comma, whether, in fact, the sentence, as a whole, needed that many commas, or not. During the first part of the 20th century, no less than George Bernard Shaw suggested an overhaul of punctuation, advocating the abolishment, for example, of apostrophes in contractions.