From Edgar Allan Poe’s Marginalia (Part XI, Graham’s Magazine, February 1848; the reader should be warned that he is using, and punning on, the now obsolete point ‘punctuation mark’):
That punctuation is important all agree; but how few comprehend the extent of its importance! The writer who neglects punctuation, or mis-punctuates, is liable to be misunderstood — this, according to the popular idea, is the sum of the evils arising from heedlessness or ignorance. It does not seem to be known that, even where the sense is perfectly clear, a sentence may be deprived of half its force — its spirit — its point — by improper punctuations. For the want of merely a comma, it often occurs that an axiom appears a paradox, or that a sarcasm is converted into a sermonoid.
There is no treatise on the topic — and there is no topic on which a treatise is more needed. There seems to exist a vulgar notion that the subject is one of pure conventionality, and cannot be brought within the limits of intelligible and consistent rule. And yet, if fairly looked in the face, the whole matter is so plain that its rationale may be read as we run. If not anticipated, I shall, hereafter, make an attempt at a magazine paper on “The Philosophy of Point.”
In the meantime let me say a word or two of the dash. Every writer for the press, who has any sense of the accurate, must have been frequently mortified and vexed at the distortion of his sentences by the printer’s now general substitution of a semicolon, or comma, for the dash of the MS. The total or nearly total disuse of the latter point, has been brought about by the revulsion consequent upon its excessive employment about twenty years ago. The Byronic poets were all dash. John Neal, in his earlier novels, exaggerated its use into the grossest abuse — although his very error arose from the philosophical and self-dependent spirit which has always distinguished him, and which will even yet lead him, if I am not greatly mistaken in the man, to do something for the literature of the country which the country “will not willingly,” and cannot possibly, “let die.”
Without entering now into the why, let me observe that the printer may always ascertain when the dash of the MS. is properly and when improperly employed, by bearing in mind that this point represents a second thought — an emendation. In using it just above I have exemplified its use. The words “an emendation” are, speaking with reference to grammatical construction, put in apposition with the words “a second thought.” Having written these latter words, I reflected whether it would not be possible to render their meaning more distinct by certain other words. Now, instead of erasing the phrase “a second thought,” which is of some use — which partially conveys the idea intended — which advances me a step toward my full purpose — I suffer it to remain, and merely put a dash between it and the phrase “an emendation.” The dash gives the reader a choice between two, or among three or more expressions, one of which may be more forcible than another, but all of which help out the idea. It stands, in general, for these words — “or, to make my meaning more distinct.” This force it has — and this force no other point can have; since all other points have well-understood uses quite different from this. Therefore, the dash cannot be dispensed with.
It has its phases — its variation of the force described; but the one principle — that of second thought or emendation — will be found at the bottom of all.
(Via The Daily Growler.)
A few points: Presumably he pronounced rationale the old-fashioned four-syllable way (rash-ə-NAIL-ee), reflecting its status as the neuter form of the Latin adjective rationalis; this is the pronunciation given in the first edition of the OED, and Fowler, writing in the early 1920s, still gives it as preferable, saying “confusion with such French words as morale & locale (there is no French rationale) leads to its being sometimes mispronounced.” (I love that “sometimes”! Surely by then he was constantly assaulted by the vile new pronunciation, which of course all the defenders of proper English now accept without cavil.)
Also, note the ital quote in “or, to make my meaning more distinct“; a French equivalent was just remarked on in this post.
Finally, I’m curious about the quotation he’s alluding to in “which the country ‘will not willingly,’ and cannot possibly, ‘let die.’” If you google “will not willingly let die,” you get a whole bunch of hits referring to the meteorologist Cleveland Abbe‘s statement, in an 1869 letter to his father discussing his creation of the scientific weather forecast, “I have started that which the country will not willingly let die” (or, in some accounts, “We have begun work that the country will not willingly let die”). The problem is that Poe’s piece appeared in early 1848, when Abbe was nine years old. Poe must be referring to some earlier piece of rhetoric; does anyone have any idea what it might be?
Oh, and my title is a pun on Mallarmé’s sonnet “Le tombeau d’Edgar Poe” (with its famous line “Donner un sens plus pur aux mots de la tribu”); tiret is the French word for ‘dash’ (the punctuation mark).