The Hupomnemata

a material record of things read, heard, or thought, thus offering them up as a kind of accumulated treasure for subsequent rereading and meditation.

the intent is not to pursue the unspeakable, nor to reveal the hidden, nor to say the unsaid, but on the contrary to capture the already-said, to collect what one has managed to hear or read, and for a purpose that is nothing less than the shaping of the self.

Source: Foucault, Michel. Self-Writing.