I believe that Philosophy is merely a synonym of Thaumaturgy, miracle-works/magic. One man's belief can change another man's reality, that is to say his perspective of reality(the reason for saying another "man's reality, but not the whole of reality). Ergo, a single demiurge can chain-react into an explosion of globally significant actions, effecting not just one man, but many or even all of world. However, this is not to say that one man's strong opinion can change the world, but that it can influence others who carry out acts which change the world. For instance, Hitler. While he was the main orchestrator, it was not he who actually committed the horrifying acts of the Holocaust, it was those who let themselves be influenced by this opinion, his Philosophy.
Today, we must be wary of both our influences on others and our actions that manifested through another's influence. While they may have planted the idea, it was you who nurtured it into reality.