[hopelessgoat]

Psychoanalytic philosopher Slavoj Žižek says that beyond these three categories there is a fourth, the unknown known, that which we intentionally refuse to acknowledge that we know: "If Rumsfeld thinks that the main dangers in the confrontation with Iraq were the 'unknown unknowns', that is, the threats from Saddam whose nature we cannot even suspect, then the Abu Ghraib scandal shows that the main dangers lie in the "unknown knowns"—the disavowed beliefs, suppositions and obscene practices we pretend not to know about, even though they form the background of our public values."

[tsunamifury]

I believe in that speech Žižek was just referring to assumptions -- i.e. the things we don't know we assumed, but are acting on subconsciously. The famous slide of how to invade Iraq made the invasion look simple and definable -- but in fact that assumption proved very wrong.

[opportune]

" just referring to assumptions -- i.e. the things we don't know we assumed, but are acting on subconsciously"

This is much, much more than "just assumption" to Zizek. In fact, this is what he refers to as ideology and it's basically the main subject he is known for

[tsunamifury]

Sure, assumptions are shorthand ideology for the brain.

[ghda]

Invading Iraq was easy, the problems all arose at the “okay, now what?” level.

[dredmorbius]

That's part of the classic formulation, which dates to the 1960s, and which I first encountered in the 1980s in print. It's effectively a "consultant's matrix' of "known" and "unknown", giving a matrix of four elements: {KK, KU, UK, UU}.

The notion of unknown knowns strongly resembles the apocryphal Mark Twain quote; "It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so". (There's no apparent proof he'd said or written this.)

https://quoteinvestigator.com/2018/11/18/know-trouble/

[_1tan]

Care to share the source? Thanks in advance.

[Jtsummers]

http://www.lacan.com/zizekrumsfeld.htm

They just quoted the wikipedia article (without attribution). It, in turn, cites the link above.