Monday, 30 April 2012

Contextualism as Solution to Scepticism

Contrary to the claims the of invariantists, contextualists hold that the conditions of knowledge change in relation to the specific context. Proposition A can be counted as piece of knowledge in one context but not considered knowledge in another varied context. The central contention of contextualist is that the legitimacy of claims about possessing knowledge vary - knowledge ascription is set to lower and higher standards dependent on the context. 

DeRose outlines an example which clearly illustrates of how knowledge ascription varies with context. 

  • In the first case outlined by DeRose, a man facing a long queue at the bank on a Friday leads to him and his wife deciding come back to the bank the next day, because he knows without checking or asking that the bank opens on a Saturday. 
  • In the second case outlined in DeRose's, in another context facing the same length of queue as in the first example, he checks to see if the bank will be open tomorrow, because he has a very important cheque to pay in. 
Both cases are objectively the same with the sole exception being the importance of paying the cheque in the second situation is much greater in the second case. Knowing whether the bank is open on Saturday for DeRose, simply depends on the importance of paying the cheque into the bank. Though an invariantist will state that he either does or doesn't know that the bank is open on Saturday, regardless of the importance of the cheque. While the contextualist contends that the conditions for knowledge ascription must change with context, otherwise the conditions required for knowledge will be unrealistically high. “The contexts of my utterances in the two cases make it easier for a knowledge attribution in Case A than in Case B” (DeRose). 

Radical sceptics have come up with numerous radical scenarios that seem to deny the possibility of any knowledge at all. Arguments including Dreaming argument, Descartes Evil Demon and the famous scenario that we could be no more than brains. One the key aims of contextualism is to undermine this radical skepticism or at the very least defuse it. An recent example from contextualist literature has been used by both DeRose and Cohen to limit the skeptical threat to our everyday knowledge. This example has sometimes been referred to as the Zebra-Mule Paradox. 

The Zebra-Mule Paradox 
P= I am seeing a Zebra at the Zoo 
H= Any Sceptical scenario which contradicts the empirical proposition P (One example of such a scenario would be what in fact I'm seeing is a cleverly painted mule). 
DeRose and Cohen say that we can truly assert the following three things: 

a). I know that P (I am seeing a Zebra)
b). I do not know that not-H 
c). I know that P (that it is a zebra) only if I know that not-H (that is not a painted mule).  

DeRose and Cohen both want to say that all three of the above statements are true and that only contextualists are in a position to say this. They are all true in context. Shifts in context would all a)-c) to be true. The painted mule pay be a possible alternative to him seeing an actual mule, but it is deeply questionable whether such possibility is a relevant one. In the context off everyday life, it would be bizarre to claim that he didn't know it was a zebra. As he can tell it apart from the other animals at the zoo. For the skeptical scenario to be a relevant possibility what would be required would a huge shift in context. In such a context he would not be sure that the supposed zebra he was seeing was not in fact a mule. He also knows as rational individual that if he doesn't know this, then he cannot know that it is a zebra. The knowledge of c) only comes into play when the observer becomes unsure of what they are seeing. But in a normal circumstance such a possibility isn't relative. 

Contextualism has also been used to show how other forms of scepticism don't pose a real threat to our everyday knowledge. A good example of this comes in the form of the contextualist reply to Peter Unger's flatness scepticism. Due to the fact that absolute terms such as flat can never really be applied to the world as no surface is absolutely flat as there is always the possibility of their being a flatter surface. Unger say's that this also applies to the term certain, it is logically necessary that if something is certain, then there is nothing which can be more certain. This leads Unger to the conclusion that certain knowledge is quite impossible. Cohen has adapted this and shown how this doesn't represent a problem for the Contextualist. For Cohen it is true to say that objects are flat in context while denying their flat in other contexts. And we can raise or lower the standards of what counts a flat dependent on the context in question. Talking about a flat cricket pitch is very different from talking about a flat pool table. 

One of the biggest criticisms of contextualism is that the arguments put forward by contextualists are ad hoc reactions devised for the sole purpose of protecting everyday knowledge against the threat of scepticism. But the contextualist approach towards knowledge seems particularly compelling as it does seem that we do lower and raise the standards of knowledge depending on the context in question. 

Sunday, 29 April 2012

The Problem of Color

The Newtonian physics of the 17th Century was responsible for reviving the atomism of the Ancient Greeks. One of the main implications of the rise of Newtonian physics for Philosophy, was that many of the physical qualities traditional associated with material objects were taken to be mere products of the mind. The qualities of color, sound and scent were determined to be produced by the mind as the physics of the age showed that these qualities were not present in the objects themselves. Leading Philosophers of the time such as John Locke determined these to be secondary qualities, in virtue of them not being present in the object in itself. Leading many to conclude that outside of us, all that objectively exists is nothing but colorless, scentless atoms moving in empty space. 

Many philosophers contemporary and 20th Century philosophers have been deeply skeptical about this conclusion. Philosophers of this ilk have included Wittgenstein, Hacker and A.N Whitehead. Hacker stated that When we are not under the sway of the magic of philosophy and misconstrued natural science, we do not think that colours are but ‘sensations in the sensorium’, as Boyle and Newton claimed. On the contrary, we think that geraniums are red and delphiniums blue, and are amazed and baffled to be told that they are ‘in and of themselves’ without colour.” (Appearance and Reality p.38) Hacker's sentiment really gets to the heart of the question of color, that our experience of the world and how we talk about it radically diverges from the scientific account of the world. 

So is the world really colored or not? Is what perceive when we open our eyes in the morning and we witness the bright and vivid is an objective quality of the world or is it merely a product of the world. This issue has been highly debated ever since it received its first modern formulation in the writings of Locke. This leads us on what might be colored in the world, there have been multiple things that have been postulated as being colored. 

So What kind of things might be considered colored? 

  • Physical Objects - Almost always seem to be colored to humans. A few unusual cases such as transparency.
  • Light - Newtonian physics holds that light white is composed of the full color spectrum. 
  • The image - As it forms on the retina is experienced as colored. 
  • The experience of color in the brain - problematic seems to suffer from the homunculus fallacy and seems problematic from ontological point of view. 
  • Overall perceptual experience - almost always reported as colored except in cases of visual defects.
  • Memory Images - Sometimes thought to be in color. 
  • Dream Imagery - Appears to be in color or is at least reported to be in color. 
If color is indeed a feature of the physical world, it appears difficult locate it. It seems odd to talk about color being in the brain as it appears like we are positing the existence of a non physical entity within the physical realm. At the worst positing color in the brain seems to suffer from the homunculus fallacy supposing that their is a little man watching and observing our color experience within our mind. Locating color as a purely mental or neurological seems to lead to color subjectivity. Locating color somewhere within in the world seems to be a problematic issue for those who want to maintain color objectivism. 

Several different positions regarding color have emerged over the year, but these positions can be divided up into three main groups regarding how they view color. 

1. Complete Subjectivism/ The Illusion Theory of Color 
Color is simply a complete illusion and only exists in the mind of the perceiver as a mental experience. With color having no objective existence. One adherent of the Illusion Theory is Hobbes who stated that colors are mere phantasms in the brain. A more modern account of the Illusion can be found in Barry Maund (2006). Galileo also adheres to the Illusion Theory of Colour, stating that “Colours... so far as their objective existence is concerned, are nothing but mere names for something which resides exclusively in our sensitive body, so that if the perceiving creature were removed, all of these qualities would be annihilated and abolished from existence”. Sometimes Locke is also taken to be a complete subjectivist when it comes to color, but is often considered take a more of dispositionalist/moderate subjectivism when it comes to color. 

2. Moderate Color Subjectivism/ Dispostional Theory of Color 
On this view color as it we know only exists in our mind, but objects are colored in one particular sense. A colored item is colored in virtue of the micro physical properties, which have the disposition to produce certain color experience in perceiver under circumstances. Locke is more commonly held to hold this position. This appears to me to be the dominant position about the issue of color at the present time. 

3. Objectivism 
Color objectivist's hold that color is an objective feature of the world in a real and substantial sense. A Yellow flag is really Yellow in the way which the term is commonly or pre-conceptually understood. Their inherent qualities of the object represent the phenomenal experience which is perceived us. Objectivism is not particular popular and generally finds few relatively supporters in the modern age, but went under somewhat of a revival under the influence of ordinary language philosophy. Defenders of this position include Whitehead, Wittgenstein and PMS Hacker. 

The Problems with Naive Realism

Naive realism, also referred to as common sense realism is a realist theory of perception, which holds we have direct awareness of the external world as it really is. A number of metaphors have been used to describe naive realism, Barry Maund describes naive realism as an window model of perception. Our use of the senses is tantamount to simply opening a window onto the external world. The use of senses discovers the world with its sights, sounds, tastes, smells and textures and represents them to us exactly as they are. Another metaphor oft used to describe the tenets of Naive realism is the camera shot model of perception, applying the metaphor to visual experiences only. The underlying idea is that looking at the world is analogous to taking a picture of the world and reproducing an exact picture of the contents and qualities of the world. The naivety of naive realism lies in the fact naive realism is a pre-scientific and pre-conceptual view of perception. For a great deal of the 20th Century Naive Realism was a distinctly unfashionable view of perception with indirect realism and sense datum theories ruling the day. 

The naive realist makes several claims about perception which should be fully and clearly outlined before we go onto discuss objections to the theory. 

  1. Objects exist independently of any perception of them. 
  2. Perception gives us immediate and direct perceptual contact with independent material objects. 
  3. Perceptions of these independent objects exactly resemble the 
  4. Independent objects are the cause of our perceptual experiences. 
  5. The perceiver contributes nothing to the perception and merely passively records the objects of perception. 
With all that we know about physics and perception is the theory of naive realism, really tenable? 

Problems for Naive Realism 

1. Problem of Secondary Qualities and Other Scientific Problems
  • Our knowledge of Newtonian and non Newtonian physics seems to tell us that material objects do not have some of the inherent properties to which common sense would attribute to them. For example we know that colors arise from the micro physical surface structure of objects. The colors we perceive are caused by how the micro physical structure of objects reflects or absorbs light. It seems that in the objective world independent of biased perceivers these qualities do not exist. It's questionable whether a distinction between Secondary and Primary Qualities makes sense, Bishop Berkeley pointed out it wasn't possible conceive of a colorless object. While A.N Whithead described the separation of Primary and Secondary Qualities as a scientific abstraction which has been falsely taken a objective truth.
  • The Problem of Empty Space: according post Newtonian physics objects that appear to be solid and substantial to us, consist of mainly empty space. The positive and negative electric charges of the micro physical level are what ultimate physical reality is solely composed of. It is argued that if you accept the account of modern post Newtonian physics then Naive realism cannot possibly true. Eddington's famous two tables comment offers one of the best expositions of this: I have settled down to writing these lectures and have drawn up my chairs to my two tables. Two tables! Yes; there are duplicates of every object about me—two tables, two chairs, two pens…One of them has been familiar to me from earliest years. It is a commonplace object of that environment which I call the world…It has extension; it is comparatively permanent; it is coloured; above all it is substantial…Table No. 2 is my scientific table. It is a more recent acquaintance and I do not feel so familiar with it…My scientific table is mostly emptiness. Sparsely scattered in that emptiness are numerous electric charges rushing about with great speed; but their combined bulk amounts to less than a billionth of the bulk of the table itself…There is nothing substantial about my second table. It is  nearly all empty space—space pervaded it is true by fields of force, but these are assigned to the categories of ‘influences’ not of ‘things’. 
2. Relativity and Perspective 
  • Species relativity presents a problem for Naive realists, as the range of sensory experience varies significantly from species to species. With their being such a huge variability between various species, how can humans claim their experience represents the objective world. For example we know cows can see larger amount of the visual spectrum than we can and dogs can hear a wider range of sound frequencies. 
  • Human perspectives, normally we can only see a part of the surface of the object at one time, at a particular angle or in a particular light. As we only ever have sensory experience of a very limited amount of the world at any one time. This makes it seem very probable that the world can not be exactly as we experience it. 
  • Unique perspective of the world, each person has a distinctly unique perspective of the world, each persons perspective to the world is different we can rarely ever have the same experience of the world. There is also plenty of evidence to suggest perception varies between individuals. 
3. Time Lag Argument 
  • Often considered the knock down argument against Naive realism. The time lag argument is another scientific argument against the naive realists view of perception. It takes eight minutes for the light from the sun to reach earth and from very distant stars it can take millions of years, by the time this light reaches earth. Many of the stars we see in the sky are dead by the time the light from them reaches us. Many people think the problem can be dissolved by taking an adverbialist approach. By describing our experience of seeing a star in the sky in a different way we can avoid the stating that we are seeing a star that has been dead for millions of year. Instead something like, 'The star appeared white-ly to me' would avoid the problem. But even with the closest objects their is a minimal time lag, which seems to harder to explain away by taking an adverbialist approach.  
Other more nuanced complaints have also been made about Naive Realism, but under the criticism from these complaints alone the position of the Naive realist seems rather untenable. 

The Tripartite Definition of Knowledge

The definition of Knowledge as justified true belief, also known as the tripartite definition of knowledge has long and distinguished history and can be traced back to at least the Platonic dialogues. In Plato's dialogue Theaetetus, it is remarked that Theaetetus 'once heard that someone suggesting that true belief accompanied by a rational account is knowledge, whereas true belief unaccompanied by a rational account is distinct from knowledge'. (Plato 1987:201c-d). In this particular example the rational account consists in the justification for the true belief to count as knowledge. More recent adherents to Knowledge as Justified Belief include A.J Ayer who set out in his essay 'The Right to Be Sure' a version of the tripartite definition of knowledge. Ayer states that the sufficient conditions for knowledge as 'first that what one said to know is true, secondly that one be sure of it, and thirdly that one should have the right to be sure'(Ayer 2009:13). With justification just being synonymous for Ayer with being the right to be sure. You can see the difference between the formulation outlined by Ayer and Theaetetus but this distinction is purely how the tripartite definition of knowledge is phrased.

The Standard Tripartite Definition of Knowledge can be outlined as:  
s knows that p if: 
  1. P is true.
  2. S believes that p. 
  3. S has justification for his belief that p. 
There has been some discussion about whether justification and belief are necessary for knowledge. While it's possible to provide counter examples where it appears that a person can have knowledge without either one of justification or belief. The most notable example of such discussion is Colin Radford's example of a schoolboy who is one the receiving end of rapid string of questions by a teacher loses his belief in the truth of that p, but still answers the question correctly. This appears to be a case where belief is not necessary for knowledge, such examples are highly contentious. It also seems that the student provision of the correct answer is in some way indicative for a belief that p is true, otherwise any answer would be equally as conceivable. It was generally accepted that the standard tripartite definition of knowledge taken together provides sufficient conditions for knowledge ascription. 

This consensus was radically undermined when Edmund Gettier published a 3 page article called 'Is Justified True Belief Knowledge?' which appeared to destroy the standard tripartite definition of knowledge. Gettier provided two counter examples which appeared to undermine the tripartite definition of knowledge. He concluded that the two counter examples showed that the 'definition [of knowledge as justified true belief] does not state a sufficient condition for someone's knowing a given proposition.' (Gettier 2009:15) While the two examples originally provided by Gettier are valid they aren't particularly realistic. But it soon became apparent that it was possible to create numerous Gettier style counter examples and many valid counter examples have been formed. The classic example offered by Gettier is the case of Smith: 
Smith has applied for a job, but, it is claimed, has a justified belief that "Jones will get the job". He also has a justified belief that "Jones has 10 coins in his pocket". Smith therefore (justifiably) concludes  that "the man who will get the job has 10 coins in his pocket".In fact, Jones does not get the job. Instead, Smith does. However, as it happens, Smith (unknowingly and by sheer chance) also had 10 coins in his pocket. So his belief that "the man who will get the job has 10 coins in his pocket" was justified and true. But it does not appear to be knowledge.(Wikipedia Gettier problem)  

Numerous early responses to Gettier were touted to solve the problem with the traditional account of knowledge. Dretske's outlined a response that stated the reasons given in the justification of a knowledge claim must be the right ones, namely they must be strong enough to be conclusive. This is similar to the response made Chisholm which stated the evidence must be adequate. What is generally deemed wrong with these responses is that they set the bar of what counts as knowledge to high which in itself is problematic. It should be also noted that Gettier style counter examples can be produced that provide examples where the justification is based on stronger evidence. Again another related response outlined by both Lehrer and Swain set out what it can be called the indefeasibly reply. The situation must be that further information would not defeat the justification. Again this seems to set the bar for what counts as knowledge far to high, it's possible to think of plenty examples where some other conceivable piece of knowledge might defeat the justification.   

A number of alternative definitions of knowledge have also been offered, probably the most influential is Goldman's causal theory. For Goldman, S knows that p if and only if fact that p is causally connected in an appropriate way with S's believing that p. It seems that this approach seems to work in dealing with Gettier style counter examples (try it on a few examples). There are a still a couple of problems with the Causal theory as outlined by Goldman. One of the said problems is that is highly debatable that facts can stand in causal relationships arguably only events and agents can stand in causal relationships. Their are also other problems surrounding  the knowledge of universals and abstract mathematical objects (Goldman: says the causal account of knowledge only applies to empirical knowledge).  

By the far the most influential reply to the Gettier problem is Nozick's Conditional Theory which outlines Knowledge as truth tracking. Nozick's theory can be seen as an attempt to avoid problems with earlier causal theory and also an attempt to synthesize the best insights for earlier replies. Nozick's Conditional Theory:
  1. p is true
  2. S believes that p
  3. if p were true, S (using M) would believe that p
  4. if p weren't true, S (using method M) wouldn't believe that p
This seems to avoid all the problems faced by the other replies as well as providing a reply to Gettier cases. Saul Kripke offered a counter example to Nozick's second formulation of his conditional theory, but Nozick denies this counter example undermines his theory as he believes that Kripke's example fulfills all of the four criterion for knowledge. 

The Background of Kant's Critique of Pure Reason Basic

It can be argued that Kant's Critique of Pure Reason is one of the most important works of modern philosophy. It can also be argued that it is one of the most difficult philosophical treatises ever written with scholars still debating exactly what Kant intended to say. To paint a complete picture and accurate picture of Kant's work would near impossible in the form of a blog. But today I intend to outline a brief and accessible description of the background against which the Critique of Pure Reason was written.  

Kant remarked famously in his Prolegomena to Any Future Metaphysics (intended to be a more accessible text outlining some of the key points of the critique), that it was David Hume who awoke Kant from his dogmatic slumbers. The dogmatic slumbers of which Kant is talking about is the acceptance of the Leibniz-Wolffian philosophy that was dominant tradition in academic philosophy in Germany at the time. While Kant's pre-critical writings are predominately Leibniz-Wolffian in nature it is apparent that he was never satisfied with the philosophy as such. Leibniz-Wolffian philosophy can be described as a rationalistic philosophy. Rationalism derives all claims to knowledge through the exercise of reason. Leibniz contended that human understanding contains within itself principles that are known to be intuitively and can be used to form the axioms of a complete description of the world derived from reason. Providing a picture of the world as it is, rather than from any particular experiential perspective or point of view. 

Conversely the man who awoke Kant from his dogmatic slumbers, David Hume, held a somewhat  opposing view. Hume an empiricist denied the possibility of knowledge through reason alone as reason cannot operate without ideas and ideas can only acquired through experience by way of the senses. The content of every thought must be in some ultimate way be derived from experience at least originally. Hume divides all human understanding into categories 'Matters of fact' and 'Relations of ideas'. Matters of fact are essentially empirical propositions that can be known through reference to experience. Knowledge through reason however is limited to consisting in relations between ideas, the truth of the proposition that 'All Unmarried Men are bachelors' derives it's truth from the relations between the ideas contained in the sentence. Other examples of a relation of ideas for Hume are the propositions of geometry and mathematics. Hume has also been taken to be a rather radical skeptic about several issues including the nature of the self, the existence of an external world and what most worried can't about induction and causation. Whether Hume was such a radical skeptic as he is often portrayed is debatable with some reading his works as providing a more naturalistic account (see Galen Strawson).  

The problem with Hume's empirical method and skepticism was that it reduced all knowledge about the world to the point of view of an individuals own experience. The skepticism that Hume is often taken as endorsing is clearly intolerable and it is no wonder that it awoke Kant from his dogmatic slumbers. It was through what Kant perceived was wrong with both the philosophies of Leibniz and Hume to the outlook that he adopted in the Critique of Pure Reason. Neither experience or reason alone is sufficient for knowledge, it is only through the synthesis of the two that Knowledge can be obtained. Knowledge obtained through the synthesis of the two is both objective and transcends the point of view of the individual observer making legitimate claims about the external world. There however remains a limit on the knowledge that can be obtained through the synthesis of knowledge, we cannot obtain knowledge of the objective world 'as it is inself' independent of any possible experience or point of view. Kant aims to achieve this with the introduction of the novel concept synthetic a priori knowledge. As content with out concepts and concepts without content are both empty notions.  

What then is the aim of the Critique of Pure Reason? Kant attempts to steer a path between rationalism and empiricism while making reference to possible experience. Opposing Hume by demonstrating that synthetic a priori knowledge is possible and offering examples of such knowledge in order to counter act Humean skepticism. While also opposing the Wolffian-Leibniz view that reason alone can provide knowledge of the world as it is in itself. It is common for Kant commentators divide the Critique into two halves. The first being the 'Analytic' positive project showing the Humean skeptic how knowledge is possible. The second being the 'Dialectic' negative half showing how reason alone can not provide knowledge of the world.