ទស្សនវិជ្ជា: សនិទាននិយម និង ពិសោធន៍និយ[[ម]]

សនិទាននិយម និង ពិសោធន៍និយម 

thumb|René Descartes
Rationalism is any view emphasizing the role or importance of human reason. Extreme rationalism tries to base all knowledge on reason alone. Rationalism typically starts from premises that cannot coherently be denied, then attempts by logical steps to deduce every possible object of knowledge.

The first rationalist, in this broad sense, is often held to be Parmenides (fl. 500 BC), who argued that it is impossible to doubt that thinking actually occurs. But thinking must have an object, therefore something beyond thinking really exists. Parmenides deduced that what really exists must have certain properties—for example, that it cannot come into existence or cease to exist, that it is a coherent whole, that it remains the same eternally (in fact, exists altogether outside time). This is known as the third man argument. Zeno of Elea (born c. 495 BC) was a disciple of Parmenides, and argued that motion is impossible, since the assertion that it exists implies a contradiction (see Zeno's arrow).

Plato (427–347 BC) was also influenced by Parmenides, but combined rationalism with a form of realism. The philosopher's work is to consider being, and the essence (ousia) of things. But the characteristic of essences is that they are universal. The nature of a man, a triangle, a tree, applies to all men, all triangles, all trees. Plato argued that these essences are mind-independent "forms", that humans (but particularly philosophers) can come to know by reason, and by ignoring the distractions of sense-perception.

Modern rationalism begins with Descartes. Reflection on the nature of perceptual experience, as well as scientific discoveries in physiology and optics, led Descartes (and also Locke) to the view that we are directly aware of ideas, rather than objects. This view gave rise to three questions:

 Is an idea a true copy of the real thing that it represents? Sensation is not a direct interaction between bodily objects and our sense, but is a physiological process involving representation (for example, an image on the retina). Locke thought that a "secondary quality" such as a sensation of green could in no way resemble the arrangement of particles in matter that go to produce this sensation, although he thought that "primary qualities" such as shape, size, number, were really in objects.
 How can physical objects such as chairs and tables, or even physiological processes in the brain, give rise to mental items such as ideas? This is part of what became known as the mind-body problem.
 If all the contents of awareness are ideas, how can we know that anything exists apart from ideas?

Descartes tried to address the last problem by reason. He began, echoing Parmenides, with a principle that he thought could not coherently be denied: I think, therefore I am (often given in his original Latin: Cogito ergo sum). From this principle, Descartes went on to construct a complete system of knowledge (which involves proving the existence of God, using, among other means, a version of the ontological argument). His view that reason alone could yield substantial truths about reality strongly influenced those philosophers usually considered modern rationalists (such as Baruch Spinoza, Gottfried Leibniz, and Christian Wolff), while provoking criticism from other philosophers who have retrospectively come to be grouped together as empiricists.

Empiricism, in contrast to rationalism, downplays or dismisses the ability of reason alone to yield knowledge of the world, preferring to base any knowledge we have on our senses. This dates back to the concept of tabula rasa (unscribed tablet) implicit in Aristotle's On the Soul, described more explicitly in Avicenna's The Book of Healing,Sajjad H. Rizvi (2006), Avicenna/Ibn Sina (CA. 980–1037), Internet Encyclopedia of Philosophy and demonstrated in Ibn Tufail's Hayy ibn Yaqdhan as a thought experiment.G. A. Russell (1994), The 'Arabick' Interest of the Natural Philosophers in Seventeenth-Century England, pp. 224–62, Brill Publishers, ISBN 90-04-09459-8 Modern empiricism was notably expounded by Francis Bacon, John Locke in An Essay Concerning Human Understanding in 1689, and David Hume.

During this era, religious ideas played a mixed role in the struggles that preoccupied secular philosophy. Bishop Berkeley's famous idealist refutation of key tenets of Isaac Newton is a case of an Enlightenment philosopher who drew substantially from religious ideas. Other influential religious thinkers of the time include Blaise Pascal, Joseph Butler, Thomas Reid, and Jonathan Edwards. Other major writers, such as Jean-Jacques Rousseau and Edmund Burke, took a rather different path.