Profundity

Spinoza saw, and I think with great profundity, that if a falling stone could reason, it would think, "I want to fall at the rate of thirty-two feet per second per second." Free will for us—that is, when we feel desire, when we are conscious of wanting to do what we do—may be even for us an illusion.

Sedulously avoid all polysyllabic profundity, pompous prolixity, psittaceous vacuity, ventriloquial verbosity, and vaniloquent vapidity.

Pablo and Rosalind were surprised by the profundity of the child's simple question.

The situation's profundity escaped most observers.

Near-synonyms: brilliance, genius

Unfortunately, Andrew's colossal ego means people miss his profundity.

Also, he had legs which seemed to begin almost at his chest—or, rather, at his chin! Yet, for all his air of peacock-like conceit, his clothes sagged a little, and his face wore a sheepish air which might have passed for profundity.

Near-synonym: abyss

I delved the abyssal profundities of Neptune's realm.

[A] sharp-looking old dame, […] inhabited a "laigh [low] shop," anglicé [in English], a cellar, opening to the High-street by a strait and steep stair, at the bottom of which she sold tape, thread, needles, skeans of worsted, coarse linen cloth, and such feminine gear, to those who had the courage and skill to descend to the profundity of her dwelling, without falling headlong themselves, or throwing down any of the numerous articles which, piled on each side of the descent, indicated the profession of the trader below.