Locke And Leibniz example essay topic

Rene Descartes (1641) exerted a tremendous influence on developments in the fields of philosophy and science. The Frenchman was said to be an intellectual genius whose scholarly contributions extended from philosophical speculation and pure mathematics to the physiology of the animal body. Descartes is regarded by some historians as one of the founders of modern epistemology. Dissatisfied with the lack of agreement among philosophers, he saw the need for a new philosophical method - a method as rigorous as mathematics itself.

He began by questioning everything which failed to pass the test of his criterion of truth - the clearness and distinctness of ideas. It was his intention to submit every thought to test, every thought to doubt. Reasoned by Descartes: though I might doubt everything, I cannot reasonably doubt that I, the thinking doubter, exist as a res cogitans (thinking substance). And thus evolved the famous Cartesian aphorism: Cogito, ergo sum (I think therefore I am). This Descartes offered as an immediate intuition of his own thinking mind. Descartes was a interactive dualist, as he argued that a body without a soul would be an automation, completely under the mechanistic control of external stimuli and its internal hydraulic or "emotional" condition - and completely without consciousness.

On the other hand, a soul or mind without a body would have consciousness, but only of the innate ideas; it would lack the sensory impressions and ideas of material things that occupy normal human consciousness most of the time. Thus the body presumably adds richness to the contents of the soul's consciousness, while the soul adds rationality and volition to the causes of behaviour. Therefore, Descartes believed that behaviour is not the result of mind or body acting alone, but the many different possible kinds of interactions between the two. Therefore, Descartes had confidence in his clear and distinct ideas concerning the material world.

Other philosophers, however, came gradually to insist that man could experience physical substance and causal law indirectly and, on occasion, by inference only. They believed that what was needed was critical self-inspection and analysis of the content of experience, with particular stress on the origin and development of ideas. This psycho-philosophical analysis was attempted by three philosophers. The German philosophers, Leibniz and Kant developed a modified form of rationalism which consisted of a logical disquisition on the modes of activity by which the mind functions. In England, Locke attempted to trace the origin of ideas to actual experience and to disclose the laws which underlie the organization of these elements of the mind.

' 'John Locke (1690) is considered to be the first great British empiricist who declared that there were no innate ideas and that all man's knowledge of the world comes from the senses. For Locke the mind at birth is a tabula rasa (blank slate), except for the few impressions formed during prenatal existence. Thus, even the most abstract ideas, such as power, infinity, identity, and substance, arise from experience. Evidence for this assumption, Locke maintained, is based upon the facts that children are totally unaware of the most universally accepted beliefs. In addition, he supported the remarkably prophetic idea that the investigation of rare cases of adult recovery of sight following congenital blindness would shed light on the development of human perception. Locke considered two elemental kinds of experience: ideas of sensation and ideas of reflection, either of which may be simple or complex.

The former arise in the separate senses and indicate the existence of an external physical world, while ideas of reflection arise from the "perception of the operations of our own minds within us". Furthermore, the occurrence of reflective thought implies the presence of a spiritual soul, presumably the essence of life with which man is born. Galileo's distinction between primary and secondary qualities was given further consideration by Locke. Primary qualities - or extension, figure, motion, rest, solidity, and number - produce in man ideas resembling the physical world which excites them; whereas the secondary qualities are "nothing in the objects themselves, but powers to produce various sensations in us by their primary qualities" (e. g., taste, colour, sound, smell).

Locke's thinking led him to the notion of associationism, conceiving of complex ideas as the combination of simple ones. While the association of ideas (a phrase coined by Locke) or, rather, combination of simple ideas was discussed to some extent in terms of "pleasure,"natural correspondence,"chance", and "custom", definite establishment of the doctrine is credited to later writers. In early 1697, the German philosopher Gottfried Wilhelm Leibniz (1646-1716) tried unsuccessfully to get in touch with Locke (1632-1704). Liebniz had read and been impressed by Locke's recent book, An Essay Concerning Human Understanding, which discussed the nature of human knowledge from an empiricist's point of view, mentioned above. But Leibniz had also felt that Locke's empiricism had gone too far, and overlooked the role of several important properties innate to the mind.

Despite their theoretical differences, Leibniz and Locke had much in common. Both had extremely wide interests, ranging from history and economics to science and religion. Both had rejected opportunities to pursue academic careers in favour of participation in the "real world" of politics and public affairs. Politics then being largely the domain of the wealthy aristocracy, both of these middle-class men had had to function as courtiers. Also, both had tried to integrate their political ideas with a larger and general philosophy of mind, derived in part from the earlier work of Descartes. Although both Locke and Leibniz were greatly influenced by Descartes, each had reacted for and against different aspects of his system, thus heading in different directions.

Locke had accepted many of Descartes's basic ideas regarding physics and physiology, while strenuously rejecting the notion of a constantly active conscious soul, brought into the world with a ready-made supply of innate ideas. Leibniz, by contrast, strongly objected to aspects of Descartes's physics. On logical grounds, he disputed that infinitely divisible material particles could ever be taken as the ultimate units of reality. Leibniz thought there must be forces or energies that produce the impressions of matter in motion. He did agree with Descartes about the unquestionable reality of the conscious soul, however, and therefore concluded that the ultimate "substance" of the universe must be some consciousness-bearing, soul-like entity which precedes all apprehension of the physical world.

Thus he proposed a philosophy of mind emphasizing the nativist and rationalist tendencies of Descartes. Leibniz saw these differences as not so much contradicting Locke, as filling in details on points left implicit or unspoken by the Englishman. Locke had seen two sources of ideas, in the sensations of the external world and the reflections on the mind's own operations, but had not much elaborated on the latter. Leibniz argued that many of the innate tendencies and dispositions he himself emphasized were implicit in Locke's notion of reflection. In discussing precisely the same mathematical and logical proofs in which Leibniz had seen evidence for innate "necessary truths", Locke had seen evidence of "intuitive and demonstrative knowledge", with a higher order of certainty than "sensitive knowledge". Locke took for granted the mind's own activity in processing its sensations, showing a large number of important and interesting features under the general term "reflection".

Leibniz chose to emphasize and elaborate on these features. Also, another difference was that Locke insisted the mind is not constantly active, and can sometimes be without thoughts just as the body can be without movement. On the other hand, Leibniz believed that the mind is constantly active, even during such states as dreamless sleep. From Locke and Leibniz have developed two major and often competing traditions in the history of psychology.

The empiricist, Lockean tradition has been particularly influential in English and American psychologies, which have emphasized the role of experience in forming the mind, and the functions of the mind in learning to predict and control events in the external, peripheral environment. The Leibniz ean tradition, relatively stronger in Germanic countries, has placed greater emphasis on the controlling and central functions of an active and innately given mind. Although Locke appeared to go in one hypothetical "direction" and Leibniz went in the other, Kant supported much of Leibniz's theories, and therefore headed in a similar direction to him. Immanuel Kant (1724-1804) trained in the Leibizean tradition of German philosophy, and the Scottish philosopher David Hume (1711-1776) aroused the "intellectually slumbering" Kant. Lockean empiricism and associationism to an extreme and questioning the logical status of the concept of causality - our intuitive belief that certain events have been directly "caused by" certain other previous events.

Kant responded to Hume by proposing a variation of Leibniz's nativist argument. He argued that since causality cannot be proven to exist in the external world, it is a part of our experience which we are unable to escape. It must therefore represent an innate contribution of the mind. Kant also proposed an external (or noumenal) world, which consists of raw reality or objects in a "pure" state, independent of human experience. This world is then transformed into the inner (or phenomenal) world when it encounters the human mind, which carries out this transformation.

Kant believes that human beings never directly experience the pure reality of things-in-themselves, but a series of "appearances" that are partly formed by the creative mind in the external world. Thus, the mind for Kant does not just passively reflect or record the external world, but actively participates in each person's experience of the world. Kant therefore supports Leibniz at this point, and refutes Locke's theory that the mind is passive. Although Kant often appears to take the view point of Leibniz over that of Locke, he was at one time driven back towards Locke.

In 1762, Kant expressed the opinion that an animal may have clear and distinct ideas without necessarily attaining to reason; there is a fundamental difference between distinguishing things from one another and knowing the distinction between things. If this is so, we are able to detect qualitative differences in the contents of our mind, and we are compelled to separate the natural or physical process, which results in a distinct image from the other logical activity which leads to the inner recognition of the distinction itself. This theory was then applied to Kant's idea of the soul. Rational psychology was founded on the idea of the soul as a possible object of a sensuous experience. Kant rejected this, whereas Locke did not, demonstrating their differing views once again.

Kant saw that it was not possible to speak of the soul which entered into relation with a system of pre-existing things. Therefore, it can be seen at a glance, that after Descartes, Locke took British empiricism in one direction and Leibniz and Kant took German idealists in another direction. Looking closely at the three influential philosophers, Kant supports certain areas of Locke's theories and argues against those areas of Leibniz's theories. Thus it cannot be concluded that Locke heads in a completely separate direction to Leibniz and Kant. Although it could be stated that all three travel part of the journey in a similar direction and then depart, heading in different directions. ' ' ' 'APPENDIX.

Peters, R.S. (1962) Brett's History of Psychology, London: George Allen and Unwin Ltd. Cabretta, P.J. (1967) A History Of Psychology In Outline, New York: Delta Publishing. Murphy, G. and Kovach, J.K. (1972) Historical Introduction To 'Modern Psychology, London: Routledge & Kegan Paul Limited. Fancier, R.E. (1990) Pioneers Of Psychology, London: W.W. Norton & Company. Leakey, T.H. (1990) A History Of Psychology, London.