Hugh Blair, answered from the texts and cited to the page.
Perspicuity is the fundamental quality of style — so essential that nothing can atone for its absence.1 The richest ornaments, without it, glimmer through the dark and puzzle rather than please; they are wasted, as a fine garment worn in a windowless room. Style itself I take to be the peculiar manner in which a man expresses his conceptions by means of language, and it is a picture of the ideas which arise in his mind and of the manner in which they rise there.2
Perspicuity, then, is not merely the absence of confusion; it is a positive beauty. We are pleased with an author who frees us from all fatigue of searching for his meaning, whose style flows always like a limpid stream, where we see to the very bottom.3 Quintilian put the demand at its highest: discourse ought to be obvious even to the most careless and negligent hearer, so that the sense strikes his mind as the light of the sun does our eyes, though they are not directed upward to it.4
Mankind are too indolent to relish the labour of reading a sentence twice; they may pretend to admire the author's depth after they have discovered his meaning, but they will seldom take up his work a second time.5 The study of perspicuity divides naturally into two parts: the choice of single words and phrases, and then the construction of sentences.6
At the level of words, three qualities are required — purity, propriety, and precision. Purity is the use of such words and constructions as belong to the idiom of the language, excluding what is imported, obsolete, newly coined without authority, or ungrammatical. Propriety is the selection of those words which established usage has appropriated to the ideas we intend to convey — the correct and happy application of them, as opposed to vulgarisms or expressions less significant of our meaning.7
A style may be pure without being proper: all its words drawn from the general mass of English, yet chosen unhappily, ill-adapted to the subject, not fully expressive of the author's sense. But where both purity and propriety meet, they do more than secure perspicuity — they render style graceful.8 The standard for both is the practice of the best writers and speakers, nothing else.
Perspicuity, it will be readily admitted, is the fundamental quality of style; a quality so essential in every kind of writing, that for the want of it, nothing can atone. Without this, the richest ornaments of style only glimmer through the dark; and puzzle, instead of pleasing the reader.Lectures on Rhetoric and Belles Lettres
The best definition I can give of it, is, the peculiar manner in which a man expresses his conceptions, by means of language... style is nothing else than that sort of expression which our thoughts most readily assume.Lectures on Rhetoric and Belles Lettres
We are pleased with an author, we consider him as deserving praise, who frees us from all fatigue of searching for his meaning; who carries us through his subject without any embarrassment or confusion; whose style flows always like a limpid stream, where we see to the very bottom.Lectures on Rhetoric and Belles Lettres
Discourse ought always to be obvious, even to the most careless and negligent hearer: so that the sense shall strike his mind, as the light of the sun does our eyes, though they are not directed upwards to it.Lectures on Rhetoric and Belles Lettres
Mankind are too indolent to relish so much labour. They may pretend to admire the author's depth, after they have discovered his meaning; but they will seldom be inclined to take up his work a second time.Lectures on Rhetoric and Belles Lettres
The study of perspicuity requires attention, first, to single words and phrases, and then to the construction of sentences.Lectures on Rhetoric and Belles Lettres
Purity is the use of such words, and such constructions, as belong to the idiom of the language which we speak... Propriety is the selection of such words in the language, as the best and most established usage has appropriated to those ideas which we intend to express by them.Lectures on Rhetoric and Belles Lettres
style cannot be proper without being also pure; and where both purity and propriety meet, besides making style perspicuous, they also render it graceful.Lectures on Rhetoric and Belles Lettres