I'm trying to understand whether you're asking or commenting. The original quote suggests that you place yourself in the moment, acknowledge solidity, thereby creating solidity. It's a simple function of developing reason in children. We stress the importance of reason, of judgment between good and evil, right and wrong, true and false. The child develops faith in "real". At this point in his/her life, real takes concrete shape. Language and memory take root, become the definition of right.
You refer to a bunch of different philosophies in a couple of quick thoughts. You have Descartes' self-proving declaration, which is less about faith and more about sophistry; and you have Levinas' concept of the Other--a briliant concept I'd love to discuss. Help me out here: what are you suggesting?
TBT