I introduced the series of articles on Research Paradigms by listing all the different paradigms, also called philosophical perspectives, philosophical epochs or, sometimes also called the “isms”. This articles deals with the first paradigm, namely Rationalism.

Rationalism took shape in modern times as an integral system of epistemological views, as a result of the development of mathematics and the natural sciences. It postulates that truth can be discovered through reason and rational thought. Rationalists assume that the world is deterministic and that cause and effect holds for all events. There are significant ways in which our concepts and knowledge are gained independently of sense experience. They also assume that these can be understood through sufficient understanding and thought. A priori (prior to experience) or rational insight is a source of much knowledge. Sense experience, on the other hand, is seen as being too confusing and tentative.

Rationalists generally develop their view in two ways. First, they argue that there are cases where the content of our concepts or knowledge outstrips the information that sense experience can provide. Second, they construct accounts of how reason in some form or other provides that additional information about the world.

Rationalism adopts at least one of three claims: the intuition/deduction thesis, the innate knowledge thesis or the innate concept thesis.

The intuition/deduction thesis claims that some propositions in a particular subject area are knowable by us by intuition only while others are knowable by being deducted from intuited propositions. Intuition is regarded as a form of rational insight. Intellectually grasping a proposition, we just “see” it to be true in such a way as to form a true, defensible belief in it. Deduction is a process in which we derive conclusions from intuited premises through valid arguments, one in which the conclusion must be true if the premises are true. Intuition and deduction thus provide us with knowledge a priori, which is to say knowledge gained independently of sense experience.

Innate knowledge means having knowledge of some truth is a particular subject area. Like the intuition/deduction thesis, the innate knowledge thesis also asserts the existence of knowledge gained a priori, independently of experience. The difference between the intuition/deduction thesis and the innate knowledge thesis rests in the accompanying understanding of how this a priori knowledge is gained. The intuition/deduction thesis cites intuition and subsequent deductive reasoning. The innate knowledge thesis offers our rational nature. Our innate knowledge is not learned through either sense experience or intuition and deduction. It is just part of our nature. Experiences may trigger a process by which we bring this knowledge to consciousness, but the experiences do not provide us with the knowledge itself. It has in some way been with us all along.

According to the innate concept thesis some of the concepts are not gained from experience – they are part of our rational nature. While sense experiences may trigger a process by which they are brought to consciousness, experience does not provide the concepts or determine the information they contain. The content and strength of the innate concept thesis varies with the concepts claimed to be innate. The more a concept seems to be removed from experience and the mental options we can perform on experience the more plausible it may be claimed to be innate.

The above three thesis are necessary for a paradigm to be rationalist. The indispensability of reason thesis and the superiority of reason thesis may also be adopted by rationalists, although they are not essential. The indispensability of reason thesis claims that the knowledge that we gain by intuition and deduction and the knowledge that are innate to us could not have been gained through sense experience. The superiority of reason thesis claims that the knowledge we gain by intuition and deduction or have innately is superior to any knowledge gained by sense experience.

Rationalism is challenged by positivism, which seeks empirical evidence rather than relying on the perceived unreliability of individual thinking. It is also opposed by empiricism on the question of the source of knowledge and the techniques for verification of knowledge.