though your reasons seem inwardly to yourself somewhat substantial, and your persuasions pithy in your own conceit, yet being well-weighed without, they be shadows without substance, and weak without force.
John Lyly. Euphues: The Anatomy of Wit (1578)
---
the comparison of Phaëton was so obvious, that he could not forbear applying it, although I did not much admire the conceit.
Jonathan Swift. Gulliver’s Travels (1726)
---
But in a fiction, in a dream of passion, Could force his soul so to his own conceit
William Shakespeare. Hamlet
---
The most grotesque and fantastic conceits haunted him in his bed at night.