Ostensive definition: defining an object by pointing to it; a dictionary comprised of actual objects.
A cardinal rule of good writing is that no literary production - novel, essay, aphorism, memoir, autobiography nor any such bijou - should commence with the word "I". To do so immediately circumscribes the purview of what follows and promises no further scope to the imagination. The case is nearly the same should "I" occur somewhere within the first sentence. Even to begin with "It . . ." can be treacherous. Nonetheless, my candidate for the best opening sentence of any novel whatsoever violates the latter two of these observations. It is the initial sentence of Anthony Burgess's novel Earthly Powers: "It was the afternoon of my eighty-first birthday and I was in bed with my catamite when Ali announced that the archbishop had come to see me."
The sentence occurred to me because my next sentence trumps it, at least in the matter of prelates: I was seated on my portico yesterday afternoon when I heard a light thump and watched a cardinal somersault over the side mirror of my pickup truck. The poor chap had spied itself in the mirror and, beset by all the devils, it had rushed the intruder only to send itself ass over tincups onto the flags of the driveway, knocked silly among a tangle of garden hose.
I climbed onto the driveway, cupped him in both hands and set him in the shade on the portico to see if he might recover. He was the very ostensive definition of "crestfallen." By contrast, the female of the pair was rifling through a tray of sunflower seeds, crest erect and as perky as any member of her species. Her counterpart sat on the flags motionless for a quarter hour, finally cocked its head to one side, and relapsed into his semicoma. Eventually something startled him enough to send him careering into the nearby garden wall, where he flopped onto the driveway, sat for another moment, then fluttered off into the bushes. I haven't seen him yet today, but he is doubtless taking the day off from his clerical obligations.
In the short length of his stay under the porch shade, however, he did demonstrate a profound philosophical problem with Bertrand Russell's claim for the fundamental nature of ostensive definitions, that “all nominal definitions, if pushed back far enough, must lead ultimately to terms having only ostensive definitions.” For if we are looking to him as a defining example of "crestfallen," he did let something beside his crest fall on the flags. There is always the potential for confused messages in these matters.