In this paper, I will critically examine and compare and contrast Russell’s essay with regards to Descartes’ “First mediation”. My comparison will evolve around 3 mains points, namely (a) how preconceptions are delusory, (b) how our sensation may be deceptive in acquiring knowledge and (c) how our mental scrutiny aids us in our judgment. a) delusory preconceptions Russell makes the observation that in life, we presuppose many things which upon closer inspection are “full of apparent contradictions”.
Such contradictions are significantly apparent in the scientific field, where uncertainties and various possible scenarios (which differ from the stated hypothesis) may occur. Sensory perceptions play a large part in drawing hypothesis and reaching conclusions. In the pursuit of such truths, there is overdependence on sensation (for scientific experimentation and analysis requires visual observation). Descartes is of the same opinion that little or no knowledge is grasped sensation but rather, “by the faculty of judgment, which is in the mind” (2nd mediation P262)
Life is ultimately defined by experiences, both past and present, whereby knowledge and sensory perceptions are amorphous. In accepting knowledge as what is evident or common sense, one falls into the trap of self deception and trusting of doubtful sources. This definition, however, entails certain amount of irrationality for experience is inherently linked to sensation, which is proven to be illusory. By means of the example whereby one examines the table from different positions, Russell explains that different people observe different things, yet all arrive at the assumption that the table is rectangular.
This is due to an inherent preconception and over reliance on sensory data. Man does not reflect on what he sees. He usually assumes it to be true. As such, no truth of the table is gleaned but rather, the outward appearance is known. This leads to the conclusion that if the appearance of the table is known, therefore the table exists, which is contradictory to Descartes’ argument. Though this example, Russell emphasize that habitual assumptions cause immediate but true assumptions of the appearance of object. Descartes tries o falsify such assumptions and claims it coincides with his appearance=deceptive, therefore there is a great deceiver cheating me argument. The fallacy in depending on senses to obtain truths is echoed in Descartes mediation where he comments that wax in both liquid and solid form still remains the same wax Such an obtrusive preconception highlights how past experience leads us to construct our own conclusions. Descartes is one who is more skeptical and critical. He tries to question if the object really exist since preconceptions are wrong and cannot be depended upon.
This in turns leads to the question whereby he questions his own existence. He also aims to prove that everything gleaned from the senses is doubtful and hence wrong. Descartes hyperbolic skepticism rejects all sense data as useless and illusory. b) delusory nature of sensation Like Descartes, Russell tries to answer western philosophical questions such as the existence of things (metaphysic) and strongly opposes the Aristotelian usage of sensation as a basis to gauge reality. For Descartes, the pursuit of truth would be wholly based on his’ method of methodological scepticism.
On the other hand, Russell acknowledges that sensory data do play a part in the knowledge acquirement process. It provides the basis from which mental scrutiny begins. Such sense data (ie, touch, colour, looks) enables one to make the inference that the table exist and from there, we are persuaded that since the object has that following properties, it is henceforth concluded that it is a table. All observations, which have equal importance in hypothesis making,(eg, observing the table through the microscope and naked eye are both equally correct) supplement the final conclusion. Descartes state that all observations are false) Russell asks leading questions which in turn lead the reader to the final conclusion, that shape, size colour, texture of the table are all properties which tell us the appearance of the table.
Unlike Descartes, he does not question the existence of the table. Descartes question the existence of the table as he is not convinced that we even exist. In measurement of such properties, a certain amount of inaccuracy is obtained which is due to the existing preconception that man have. 8]In my opinion, Russell makes a more convincing argument. Sensory perceptions are important in mental thought processes. Even before one can begin intellectual inquiry, one requires some kind of visual observation. The backbone behind all scientific scrutiny was wholly based on sensory perceptions. For instance, the rule of gravity was derived when Newton observed that something is pulling all object to the ground. (Ie: he observed the apple falling) Similarly, Descartes’ interpretation “that his senses are an unreliable source” came from mental analysis of his sensory observations. 
Russell’s analogy of the table (colour, texture, shape) is akin to Descartes’ analogy of the wax. In both, it is posited that the visible manifestation of the object might change, but the essence of it remains. Such a concept cannot be attained from sensory organs (which is wholly based on appearance). Appearance and perception do not give dubitable evidence for understanding of composite things. Instead, philosophical investigations and contemplations of ideas come into play. Through mental interpretation and organization, the information that we perceive via sensation is coherently understood.
This is related to Descartes’ “dream argument”. As revealed by Descartes in his 1st mediation, “and how often, asleep at night, have I become convinced of quite ordinary things”. Man has no way of differentiating between the dream world and that of the real world. In both, the sensory perceptions are both equally real, so do thoughts and principles. It is only after one arouses from sleep that one is able to make a distinction between the two worlds. This leads to the claim that we cannot know anything about the external world through our senses.
Descartes aimed to move people away from the Aristotelian theory of knowledge, “according to which all knowledge comes from the senses” . He tries to bring skeptical hypothesis into people’s beliefs, one that would falsify most beliefs if brought in. This intent is not analogous to Russell. c) mental scrutiny as basis for judgment As far as it can be ascertained, sensory perception leads to deceptive conclusions. Difficulty arises when we recall the different manifestation of a single object, Hence, defining the essence of the object based on sense-datum (the experience gained from sensation) is intrinsically false.
Since the Aristotelian theory of knowledge via sensory perception does not suffice, another criterion is set. As postulated by Russell, a “great amount of thought enables us to know what we really may believe in”. This is inherently linked to Descartes’ “I think [therefore] I am”. By this, he means that one must have understanding about oneself, for only a conscious mind can fully grasp the faculty of the question, and thus be able to correlate sensation to understanding. To reiterate my point, I will bring forth Descartes’ observation, that we are “thinking thing” (P 258). 12] Descartes tries to prove that we might not exist. (while Russell assumes we do) While it may seem common sense, such ineffable thoughts are the only thing that cannot be doubted. This paralleled in Russell’s analysis that physical properties of the table result in us experiencing a sensation, which in turn helps us, form an accurate perception of the table.  From there, one must undergo critical thinking and mental contemplation to attain understanding of the existence of the object.
It is argued that such sense data, which leads to prove of the reality of the object are intrinsically affirmed by what we define as common sense. Common sense is something indoctrinated in us since young and is it inherent to human beings. It is the ability to use intuition with deduction to question and provide answers based on observations. However, since it is based on appearance, Descartes feels that it does not provide us with a rational framework to conduct enquires. Descartes then withholds assent from such precipitated conclusions, habitual opinions and assumptions.
Only when one takes away such preconceptions can one truly attain a better interpretation of customary knowledge. This is exemplified by Descartes’ endeavor to remove all “former opinions [and to treat them as] utterly false and delusory”. In isolation, this fashions a rational framework, whereby substantial ontological truths can be attained. Russell does not make use of such a method as his aim is not to find true knowledge on its own but to correlate knowledge with deduction.
Russell agrees with Descartes that sensation provides useful information with regards to the external world and give rise to experiences. While Russell observes that certainty can only be attained when one amalgamates observed knowledge with mental scrutiny and logical thinking, Descartes rejects sensory perceptions totally. He believes that there is a deceiver who tricks man into believing sensation equates to reality and that our existence (as well as that of the object) is debatable.
http://en. ikipedia. org/wiki/Bertrand_Russell http://www. iep. utm. edu/d/descarte. htm http://www. sparknotes. com/philosophy/meditations/ Descartes Mediation 1 and 2 ———————–  .
If our table is ‘really’ rectangular, it will look, from almost all points of view, as if it had two acute angles and two obtuse angles. If opposite sides are parallel, they will look as if they converged to a point away from the spectator; if they are of equal length, they will look as if the nearer side were longer. Russell, The problems of philosophy)  We are in the habit of judging as to the “real” shapes of things, and we do this so unreflecting that we come to think we actually see the real shape (Russell)  “I place the wax by the fire; what remained of its taste evaporates, its scent dissipates, its colours changes, its shape is lost, its size increases; it becomes liquid and hot; you can hardly touch it, and if you do it no longer makes a sound, But does the same wax remains?
It must be granted that it does” (Descartes 2nd mediation, P260)  Aristotelian philosophy claims that all knowledge comes from the senses. http://www. sparknotes. com/philosophy/meditations/section2. rhtml  Methodological scepticism : a systematic method approach to differentiate true knowledge from false beliefs by categorization and elimination of any idea that has the slightest doubt. It does not depend on whether the doubts are probable but whether they are possible.  The object is a table and it exist 7] Dream hypothesis: we could be dreaming and we might not even know that  For example, if one sees two parallel lines of a rectangular table, one would be of the common opinion that the table is rectangular.
Yet, it can be argued that such correct conclusion is not necessary always derived. Ie, the person might arrive at the conclusion that the table is square.  He found out that his senses gave him conflicting observations of what he deemed a single object (wax). Therefore it was inaccurate. 10] Dream argument, whereby people are unable to differentiate between the dream world and reality. This is contradictory to 18th century philosopher Geroge Berleley’s stand that “appearance is reality”  http://www. sparknotes. com/philosophy/meditations/section4. rhtml  By doubting and questioning, the following conclusions are obtained; that (1)someone or something is thinking, hence, he is someone , which arrives at the fact that (2)he exists.  that we cannot say that the table is sense-data, or even that even the sense-data are directly properties of the table.