If the purpose of thinking is to uncover the hiddenness of Being, how does thinking about thinking help in fulfilling the deepest aims of the human condition as Sapiens? Thinking about thinking can uncover the traps that thinking plays on us when it convinces us that we know. Thinking about thinking is necessary in order to objectify our thought, to objectify the way we objectify reality. This objectification is necessary for all learning which is primarily subjective: the first relationship we have with the word is as an appropriation of that world through the entrapment of reality that takes place as soon as we frame it within our own perception. So, thinking about thinking has to take into account the limits of that framing in order to conceive of a greater enframing[i].
This could be explained through the metaphor of the jigsaw puzzle. A subjective experience that is not deeply thought about can create a piece of the jigsaw, but it has no idea of the larger frame into which that piece can be purposefully slotted if we want to complete the puzzle. Or in other words, without deep thought about life and about how our lives are or should be conceived, we throw ourselves into the game, but without the box to guide us. We have the pieces but no idea of how the finished product should look. So, in order to complete the puzzle we need to first of all try and create a mental construct from the pieces of what the overall picture could be. If there is a lot of sky blue, then the picture is probably an outdoor scene. Can we find any grass, or rocks? Etc..
Having the pieces of the jigsaw is not enough. We need to look for the bigger picture before we can hope to slot it all together. And in order to do that we need to think about what we are thinking about.
[i] One of Martin Heidegger’s terms. See especially his essays from the The Question Concerning Technology