Context

This quote comes from the Introduction to The Critique of Pure Reason, which was published by German philosopher Immanuel Kant in 1781. 

Kant hits us with this doozie in the first paragraph of his introduction to The Critique of Pure Reason. The quote basically lays out the premise for his whole book, which is that it takes two to tango when you're creating human knowledge. For starters, you need the real world that exists outside your mind and you need your mind to make sense of this world by arranging it into categories. Without the mind's categories, all your perceptions of the world would be total gibberish.

So for Kant, there's no such thing as a thought in your head that isn't connected to something in the real world. And there's no perception of something in the world that isn't shaped by your mental concepts. It takes two, baby.

Where you've heard it

You're not likely to hear this quote in any famous movies, TV shows, or songs. But don't be surprised if someday you come across a person who just finished a first-year college philosophy course and has decided to put this quote on a T-shirt. There's no guarantee that this person will be able to explain what the quote actually means, but they'll probably think it sounds pretty cool.

Pretentious Factor

If you were to drop this quote at a dinner party, would you get an in-unison "awww" or would everyone roll their eyes and never invite you back? Here it is, on a scale of 1-10.

Quoting any philosopher is liable to make someone call you pretentious. But quoting a German epistemologist from the eighteenth century is pretty much going to make it a sure thing. If you don't believe us, just say this quote in front of a mirror and see if you can annoy even yourself.