arbitrary
capricious
careless
heedless
ill-advised
ill-considered
ill-contrived
ill-devised
ill-gauged
ill-judged
impolitic
imprudent
inadvertent
inadvisable
inconsiderate
indiscreet
inexpedient
injudicious
insensate
irrational
mindless
misadvised
misguided
myopic
reasonless
reckless
senseless
shortsighted
thoughtless
unadvised
uncalculating
unconsidered
undiscerning
unforeseeing
unguarded
unreasonable
unreasoning
unreflective
unseeing
unsensible
unsound
unthinking
unthoughtful
unwise
witless
absent-minded
bighearted
childlike
ebullient
excitable
headstrong
impulsive
inconstant
open-hearted
quick-tempered
short-tempered
undutiful
unlearned
unprogressive
unquestioning
warm-hearted
world-wearied