In some ways, World War I simply exacerbated intellectual developments that had been going on for a long time. But it certainly contributed to a sense of alienation from traditional western ideas among intellectuals. In terms of actual academic philosophy, the period after World War I saw the rise (though not the beginning) of existentialism, a philosophical movement that emphasized man's aloneness in the world, which, many existentialists held, ought to create a sense of freedom and individual responsibility. German existentialist Martin Heidegger argued for an approach that did not imagine people in terms of a metaphysical eternity, but rather in terms of their being, i.e., their life on Earth. While not a existentialist as such, Ludwig Wittgenstein claimed that philosophy was essentially incapable of providing answers to large, metaphysical questions. In general, philosophy during this period, and on into World War I, emphasized a turning away from metaphysical solutions and the comforts of religion and rationalism. World War I exacerbated this trend.