ˈmēlyəˌrizəm, -lēə- noun
( -s )
Etymology: Latin melior better + English -ism
: the belief or doctrine that the world tends to become better and that man has the power to aid its betterment
meliorism seeks a compromise between both optimism and pessimism: the world is neither good nor evil, but can be improved on the condition that its parts do their best to improve it — Frank Thilly
— compare deteriorism