or one's thoughts, can be traced to a single person:
Michel Eyquem de Montaigne, a nobleman, government official, and winegrower.
He lived in the Périgord area of southwestern France from 1533 to 1592 and invented this idea of writing about oneself so as to create a mirror in which other people could see themselves - as in, his readers would find resonance in what he wrote. It was a way of linking people...
He is therefore credited with being the first proto-blogger.