the idea

the (very) idea!

An exclamation of shocked disapproval regarding something someone said or did. They thought I would just go along with their plan to cut my pay while taking on more responsibility. The idea! The very idea—how dare you suggest something so horrible!
Farlex Dictionary of Idioms.

the idea

Also, the very idea. See under what's the idea.
See also: idea
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • gotcha
  • hoo-rah
  • viola
  • voilà
  • manual
References in classic literature
Plato uses them, though he also criticises them; he acknowledges that both he and others are always talking about them, especially about the Idea of Good; and that they are not peculiar to himself (Phaedo; Republic; Soph.).
Like Parmenides, he is overpowered and intoxicated with the idea of Being or God.
Meno
When Thorndike experimented with animals in cages, he found that the associations established were between a sensory stimulus and a bodily movement (not the idea of it), without the need of supposing any non-physiological intermediary (op.
The Analysis of Mind
"Yes, monsieur le cardinal, and that is why I venture to call the idea courageous as well as devoted.
Ten Years Later
And the idea of the State is supplemented by the revelation of a future life.
Republic
"Then," suggested the idea, with a blush for its own absurdity, "why not go on pilgrimage and seek her?
Quest of the Golden Girl
My earrings supplied me with the idea of which I was in search.
Law and the Lady
Just as he must immediately howl, he was aware that the idea, an entirely different idea, was there, in the innermost centre of the quick-thinkingness of him, with all its compulsion.
Jerry of the Islands
Wait till you see Sarah, she'll get the idea. She'll be interested.
Winesberg Ohio
To me the idea of an immediate union with my Elizabeth was one of horror and dismay.
Frankenstein
The most fundamental idea, the idea of existence, has not been received by me through sensation; indeed, there is no special sense-organ for the transmission of such an idea."
Anna Karenina
So long as the quality and the low prices can be maintained, here are two inexhaustible sources of wealth for the canton, which suggested to my mind the idea of establishing three fairs in the year.
The Country Doctor
Besides, I had ideas of many sensible and corporeal things; for although I might suppose that I was dreaming, and that all which I saw or imagined was false, I could not, nevertheless, deny that the ideas were in reality in my thoughts.
Reason For Discourse
Gervinus, Schlosser, and others, for instance, at one time prove Napoleon to be a product of the Revolution, of the ideas of 1789 and so forth, and at another plainly say that the campaign of 1812 and other things they do not like were simply the product of Napoleon's misdirected will, and that the very ideas of 1789 were arrested in their development by Napoleon's caprice.
War and Peace
The ruling ideas of each age have ever been the ideas of its ruling class.
Communist Manifesto