“It is hard to teach an old dog to sit, as well as it is difficult to teach an old Laplandian rafter to swim.”
“It's difficult to teach how to write novels, but teaching swimming is just as hard.”
“You can't teach the old maestro a new tune.”
“You can't teach an old dogma new tricks.”
“The young, in their innocence, are often wise and capable of teaching the old.”
“If a man would follow, today, the teachings of the Old Testament, he would be a criminal. If he would follow strictly the teachings of the New, he would be insane.”