Rationalism
Rationalism is a philosophical movement which
gathered momentum during the Age of Reason of the 17th Century. It is
usually associated with the introduction of mathematical methods into
philosophy during this period by the major rationalist figures, Descartes, Leibniz
and Spinoza. The preponderance of French Rationalists in the 18th
Century Age of Enlightenment, including Voltaire, Jean-Jacques Rousseau and
Charles de Secondat (Baron de Montesquieu) (1689 - 1755), is
often known as French Rationalism.
Rationalism
is any view appealing to intellectual and deductive reason (as
opposed to sensory experience or any religious teachings) as the source of knowledge
or justification. Thus, it holds that some propositions are knowable by us by intuition
alone, while others are knowable by being deduced through valid
arguments from intuited propositions. It relies on the idea that reality
has a rational structure in that all aspects of it can be grasped
through mathematical and logical principles, and not simply
through sensory experience.
Rationalists
believe that, rather than being a "tabula rasa" to be
imprinted with sense data, the mind is structured by, and responds to, mathematical
methods of reasoning. Some of our knowledge or the concepts
we employ are part of our innate rational 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, which has
in some way been with us all along. See the section on the doctrine of
Rationalism for more details.
Rationalism
is usually contrasted with Empiricism (the view that the origin of all
knowledge is sense experience and sensory perception), and it is
often referred to as Continental Rationalism because it was predominant
in the continental schools of Europe, whereas British Empiricism
dominated in Britain. However, the distinction between the two is
perhaps not as clear-cut as is sometimes suggested, and would probably
not have even been recognized by the philosophers involved. Although
Rationalists asserted that, in principle, all knowledge, including
scientific knowledge, could be gained through the use of reason alone,
they also observed that this was not possible in practice for human
beings, except in specific areas such as mathematics.
It
has some similarities in ideology and intent to the earlier Humanist
movement in that it aims to provide a framework for philosophical discourse outside
of religious or supernatural beliefs. But in other respects there is little
to compare. While the roots of Rationalism may go back to the Eleatics
and Pythagoreans of ancient Greece, or at least to Platonists and Neo-Platonists,
the definitive formulation of the theory had to wait until the 17th
Century philosophers of the Age of Reason.
René
Descartes is one of the earliest and best known proponents of Rationalism,
which is often known as Cartesianism (and followers of Descartes'
formulation of Rationalism as Cartesians). He believed that knowledge of
eternal truths (e.g. mathematics and the epistemological and
metaphysical foundations of the sciences) could be attained by reason alone,
without the need for any sensory experience. Other knowledge (e.g. the
knowledge of physics), required experience of the world, aided by the scientific
method - a moderate rationalist position. For instance, his famous dictum "Cogito
ergo sum" ("I think, therefore I am") is a
conclusion reached a priori and not through an inference from
experience. Descartes held that some ideas (innate ideas) come from God;
others ideas are derived from sensory experience; and still others are fictitious
(or created by the imagination). Of these, the only ideas which are
certainly valid, according to Descartes, are those which are innate.
Baruch
Spinoza expanded upon Descartes' basic principles of Rationalism. His
philosophy centered on several principles, most of which relied on his notion
that God is the only absolute substance (similar to Descartes'
conception of God), and that substance is composed of two attributes, thought
and extension. He believed that all aspects of the natural world
(including Man) were modes of the eternal substance of God, and can
therefore only be known through pure thought or reason.
Gottfried
Leibniz attempted to rectify what he saw as some of the problems that
were not settled by Descartes by combining Descartes' work with Aristotle's
notion of form and his own conception of the universe as composed of monads.
He believed that ideas exist in the intellect innately, but only in a virtual
sense, and it is only when the mind reflects on itself that those ideas
are actualized.
Nicolas
Malebranche is another well-known Rationalist, who attempted to square the
Rationalism of René Descartes with his strong Christian convictions and
his implicit acceptance of the teachings of St. Augustine. He posited that
although humans attain knowledge through ideas rather than sensory
perceptions, those ideas exist only in God, so that when we access them
intellectually, we apprehend objective truth. His views were hotly contested
by another Cartesian Rationalist and Jensenist Antoine Arnauld (1612 -
1694), although mainly on theological grounds.
In
the 18th Century, the great French rationalists of the Enlightenment
(often known as French Rationalism) include Voltaire, Jean-Jacques
Rousseau and Charles de Secondat (Baron de Montesquieu) (1689 -
1755). These philosophers produced some of the most powerful and influential
political and philosophical writing in Western history, and had a defining
influence on the subsequent history of Western democracy and Liberalism.
Immanuel
Kant started as a traditional Rationalist, having studied Leibniz and Christian
Wolff (1679 - 1754) but, after also studying the empiricist David
Hume's works, he developed a distinctive and very influential
Rationalism of his own, which attempted to synthesize the traditional
rationalist and empiricist traditions.
During
the middle of the 20th Century there was a strong tradition of organized
Rationalism (represented in Britain by the Rationalist Press Association,
for example), which was particularly influenced by free thinkers and
intellectuals. However, Rationalism in this sense has little in common
with traditional Continental Rationalism, and is marked more by a reliance on empirical
science. It accepted the supremacy of reason but insisted that the
results be verifiable by experience and independent of all arbitrary
assumptions or authority.