When he recorded his observations, he adhered to the Erasmian principle of distilling things down to their essence and entering them in notebooks, as if he were storing rare wine to be served for

dégustation

in future conversations.

Reading and writing were therefore inseparable activities. They belonged to a continuous effort to make sense of things, for the world was full of signs: you could read your way through it; and by keeping an account of your readings, you made a book of your own, one stamped with your personality.