foolhardy, heady, rash, reckless
Meaning: marked by defiant disregard for danger or consequences; "foolhardy enough to try to seize the gun from the hijacker"; "became the fiercest and most reckless of partisans"-Macaulay; "a reckless driver"; "a rash attempt to climb Mount Everest"
Meaning: extremely exciting as if by alcohol or a narcotic
judicious, wise, heady
Meaning: marked by the exercise of good judgment or common sense in practical matters; "judicious use of one's money"; "a wise decision"
But pray don't encourage him, as I said; for he is much too heady and precipitate as to this matter, in my way of thinking; though, to be sure, he is a very good man, and I am much obliged to him.