Seneca,
Moral letters to Lucilius — Letter 109…
“ Nevertheless, there are certain matters where even wise men see the facts more clearly in the case of others than in their own. Moreover, the wise man will, in company with his fellow sage, confirm the truth of that most sweet and honourable proverb – "always desiring and always refusing the same things": it will be a noble result when they draw the load "with equal yoke." ”
