Francis P. has an outstanding tribute to SDB's toughness here"
He who perseveres in a demanding mission despite high personal costs and a shortage of indicators of success is demonstrating toughness. Steven Den Beste, no matter how sick he was, is, or might become, has proved that he's tough as nails.
At SDB's best [no pun intended], he reminded me of Montaigne in the sense that both men's essays were written in a style that showed a mind thinking in a logical and systematic way, as opposed to a mind arguing a conclusion already drawn.
I join the chorus of those offering thanks and well wishes to SDB.