Immanuel Kant

Immanuel Kant (1724-1804) was an influential German philosopher. His main field of expertise was ethics, and quite drastically changed the field. One could say that a quick summary of his general philosophy was: "Don't lie, don't break promises". While it's a nice idea in theory, Kant did not explain which was more important, which created some problems for his followers when, say, they were asked to keep a secret, and then somebody asked them about the secret.

But this philosophy did, in a way, "birth" the idea of idealism in eastern Europe, and influenced other philosophers, such as Fichte, Hegel, Novalis, REinhol, and Schelling.

Kant also opposed democracy, and believed that, while God almost certainly doesn't exist, he is necessary for (most) societies as moral compass.

Interaction With Modern Society
Multiple groups have claimed to live by Kant's idealistic thoughts (about lying and promises), including Fox News, The Bush Administration, and The Tea Party, all of which have succesfully stood by the philosophy with nothing but stalwartism have failed miserably.