People who like thinking seem to overestimate the power of ideas in shaping the world. My interpretation is that it's probably the typical arrogance of the intellectual letting itself through.
For example, there are arguments that the renaissance was a result of the social and economic conditions created by the black death, not the intention of any human actor. The post-WW2 social wellness a result precisely of the war, and so on.
Not everybody agrees on what "improve mankind and society" should mean, so you're back to either submitting to a common concept of objective truth, where the "bad" but realistic model wins, or political arm wrestling for your ideas to win against the other's (on the basis of faith if you're in the middle ages, or whim if you're a postmodernist).
For example, there are arguments that the renaissance was a result of the social and economic conditions created by the black death, not the intention of any human actor. The post-WW2 social wellness a result precisely of the war, and so on.
Not everybody agrees on what "improve mankind and society" should mean, so you're back to either submitting to a common concept of objective truth, where the "bad" but realistic model wins, or political arm wrestling for your ideas to win against the other's (on the basis of faith if you're in the middle ages, or whim if you're a postmodernist).