Which lines from the text most clearly suggest that the narrator will fight against nature?

when i was thirteen years of age we all went on a party of pleasure to the baths near thonon. .
. .i always came from my studies discontented and unsatisfied.
i had gazed upon the fortifications and impediments that seemed to keep human beings from entering the citadel of nature.
. .what glory would attend the discovery if i could banish disease from the human frame and render man invulnerable to any but a violent death!