Stronger is not second place in a race of three — strong, stronger, strongest. Rather, it is a record of growth. Stronger is a superlative from the root word strong and can refer to physical and mental vigor.When a comparative adjective is used, it requires one to consider, than what?
One must supply the other side of the comparison. Consider the Nietzsche’s observation, “what doesn’t kill you makes you stronger.” Does this, now common, aphorism mean stronger than dead or stronger than you were before you encountered the thing that almost killed you?
As a ranking adjective, stronger tempts one compete to become the strongest. However, the record of the strongest will be surpassed, just as best, fastest, and tallest. Stronger, then, is only for today. Stronger than yesterday, perhaps. Stronger than another, sometimes.
Stronger than thought possible is the attraction of trying to become so.