What do you call someone who makes a famous saying?

I’ve heard somebody call the person who says something which becomes well known as the author but it doesn’t sound right to me.

Is it correct or is there a better word?

It should be appropriate in the sentence

• The famous saying “Every problem is an opportunity in disguise” is attributed to both John Adams and Benjamin Franklin. If I had to bet on one of them, I would go with Benjamin Franklin as the _______.

And preferably in

• Yes, both of them are ________.