You can't teach an old dog new tricks

who first said "you can't teach an old dog new tricks?"

Somebody dead, no doubt. It's usually impossible to trace traditional proverbs like that one to the first speaker. Researchers are doing well if they can determine what country a saying originated in.

The Oxford Dictionary of Proverbs gives the first *known* occurrence in the form "the dogge must lerne it when he is a whelpe, or els it wyl not be; for it is harde to make an olde dogge to stoupe". Ths is froa book of advice on husbandry by a man called Fitzherbert, published in 1530. But as Smokey says, it was probably a truism even then. (VSD)