“Reynolds said that ‘[Samuel] Johnson always practised on every occasion the rule of speaking his best, whether the person to whom he addressed himself was or was not capable of comprehending him. ‘If,’ says he, ‘I am understood, my labour is not lost. If it is above their comprehension, there is some gratification, though it is the admiration of ignorance;’ and he said those were the most sincere admirers; and quoted Baxter, who made a rule never to preach a sermon without saying something which he knew was beyond the comprehension of his audience, in order to inspire their admiration.'” — James Boswell, Life of Samuel Johnson, 1791

But:

“To write well, express yourself like the common people, but think like a wise man.” – Aristotle