Rationalism ( from the Latin ratio , " cause") is based on the assumption of a philosophical motion which is the source of all knowledge of human reasoning. Rationalism is defined in epistemology and in the modern sense as: a theory that considers logic to be the source of knowledge and the only means of proving the truth . The liberal rationalist view says that " reason is the most important factor in the acquisition of knowledge" and the extremist point of view says that " reason is the only aid to acquire knowledge". In pre-modern times, rationalism was considered synonymous with philosophy or Socrates' way of life. From the age of the development of philosophy and science, rationalism refers to the integration of mathematical methods into philosophy , as Descartes , Leibniz and Spinoza did. This is called European rationalism , because empiricism reigned in Britain when this doctrine was dominant in Europe. Rationalism is often contrasted with empiricism. In a broad sense, these two perspectives are not distinct from each other , for a philosopher can be both rationalist and empiricist at the same time. The most extreme view of empiricism states that knowledge is acquired through experience , either with the five senses or with deep feelings like pain and happiness. Experience is the basis of knowledge , and knowledge descends from experience. Conflict is basically about the source of knowledge and the proper method of verifying knowledge. Proponents of rationalism have argued that it is possible to acquire all possible knowledge from a fundamentalist principle , such as the formulas of geometry , by descending methods. Baruch Spinoza and Gottfried Leibniz were followers of this view and they gave birth to the fundamental doctrine of rationalism by fighting some of the epistemological and metaphysical problems presented by Descartes. Spinoza and Leibniz claim that theoretically all kinds of knowledge (including scientific knowledge) can be derived by reason , although they both observed that this would not be possible except in some exceptional branch like mathematics. Rationalism is the analysis of behavior based on reason.