Rationalism is a philosophical doctrine that asserts that the truth can best be discovered by reason and factual analysis, rather than faith, dogma or religious teaching. Its original roots extend at least as far back as Plato. Rationalism has some similarities in ideology and intent to humanism and atheism, in that it aims to provide a framework for social and philosophical discourse outside of religious or supernatural beliefs; however, rationalism differs from both of these, in that:
As its name suggests, humanism is centered on the dignity and worth of people. While rationalism is a key component of humanism, there is also a strong ethical component in humanism that rationalism does not require. As a result, being a rationalist does not necessarily mean being a humanist.
Atheism, a disbelief or lack of belief in God, can be on any basis, or none at all, so it doesn't require rationalism. Furthermore, rationalism does not, in itself, affirm or deny atheism, although it does reject any belief based on faith alone. Modern-day rationalism is strongly correlated with atheism, although historically this was not so. Most—if not all—prominent rationalists today, including scientists such as Richard Dawkins and activists such as Sanal Edamaruku are atheists.
Outside of religious discussion, the discipline of rationalism may be applied more generally, for example to political or social issues. In these cases it is the rejection of emotion, tradition or fashionable belief which is the defining feature of the rationalist perspective.
During the middle of the twentieth century there was a strong tradition of organized rationalism, which was particularly influenced by free thinkers and intellectuals. In the United Kingdom, rationalism is represented by the Rationalist Press Association, founded in 1899.
Rationalism in this sense has little in common with the historical philosophy of continental rationalism expounded by René Descartes and Gottfried Wilhelm von Leibniz. British empiricism of the 17th and 18th Century and logical positivism of the early 20th Century, though starkly opposed to continental rationalism, are in certain respects compatible with rationalism in the present sense. Indeed, a reliance on empirical science is often considered a hallmark of modern rationalism.
