The 18th-century German philosopher Immanuel Kant (1781) advocated a blend of rationalist and empiricist theories. In it he argued that there were fundamental problems with both rationalist and empiricist dogma. Atheist, rationalist, and humanist philosophies are also adhered by sizeable minorities. Huxley had a close association with the British rationalist and secular humanist movements. Isaac Asimov was an atheist, a humanist, and a rationalist. Kenyon is a sculptor who represents rationalist humanism. Constructivism is a theory critical of the ontological basis of rationalist theories of international relations. Dahrendorf believed in two approaches to society, Utopian and Rationalist. Pythagoras was one of the first Western philosophers to stress rationalist insight. According to the radical German rationalist and spiritualist Joh. Thinking in rationalist (foundationalist) terms will not solve this problem, he claimed. Many Hungarian Unitarians embrace the principles of rationalist Unitarianism. There is art and architecture from the Art Nouveau, Neoclassic, Modernist and Rationalist periods. He was the father and teacher of a long line of rationalist philosophers and scholars. UAAR (Union of Rationalist Atheists and Agnostics).