At a dinner party one should eat wisely but not too well, and talk well but not too wisely.
The common idea that success spoils people by making them vain, egotistic and self-complacent is erroneous; on the contrary, it makes them, for the most part, humble, tolerant, and kind. Failure makes people bitter and cruel.
Usage is the only test. I prefer a phrase that is easy and unaffected to a phrase that is grammatical.