Hmmm, mnemonic, but only partially.
"I CHOOSE" is formed as an acronym (each letter meaning a word). A mnemonic is formed of words and only the 1st letter of which means another word. (so I=integrity, and C=character).

Have we stumbled onto something new? This acronym happens to ALSO be a phrase that ALSO is related to the philosophy that the individual letter-words reference. to. My brain hurts... I think I'll just stick with acronym.