The universe has been in existence for about 13.7 billion years, human beings for maybe 60,000. How much do we know about the world in which we live, and how certain can we be of what we claim to know? Much of what commonly passes for knowledge is more problematic than it first appears to be. Knowledge itself is not static but has a history: Yesterday's revolution in thought becomes today's common sense, and today's common sense may go on to be tomorrow's superstition. Few so-called eternal truths' have in fact survived the ravages of time and it is not clear that we human beings have privileged access to any truth that there might be.

Our knowledge is, unavoidably, relative to the way we see and think about the world. A number of general factors influence the interpretations that we make. Reflection upon these factors may suggest that much 'common sense' is less obvious than it first appears. One of the aims of this course is to uncover basic means through which we interpret the world and to examine their status.

Perception

Perception is an important source of knowledge. Our sense organs provide a channel of communication between us and the world beyond. Without them, we would be insulated from the possibility of experience. The way we perceive the world depends crucially on the nature of these sense organs. Had we evolved differently our experience of the world would be different. (Imagine having eyes sensitive to light of completely different wavelengths.)

Logic

We use basic laws of logic in the attempt to achieve consistency in our thought. We also assume the truth of other principles. For example, that every event has a cause or that nature is uniform; but what is the status of laws and assumptions? In what way, if any, can they be justified?

Language

This has an important effect on the way we experience the world. Most of our knowledge comes to us linguistically encoded. This immediately raises the question of the relationship between language and the world. Does language passively describe the way the world is or does it actively structure our experience?

The Main Categories of Knowledge: Specific Problems

Mathematics

Mathematics gives us certainty, but does it tell us anything about the world? The most successful areas of knowledge in terms of their predictive power are those that are amenable to mathematical analysis. It has been suggested that the laws of nature are written in the language of mathematics. What exactly is the relationship between mathematics and the world?

Politics

We often hear about human rights, but what exactly are they, and where do they come from? Are individuals' rights absolute, or can we sometimes sacrifice them for the greater good? What is a state and why do we need one? Is democracy the best form of government, or are there other preferable alternatives; for example a benevolent dictatorship? Are people really free in a modern industrial society or are they simply tricked into believing that they are free?

Aesthetics

A good opening question is, 'What distinguishes art from non-art?' Among the traditional criteria that have been suggested are: the intentions of the creator, the intrinsic properties of the object of art and the response of the spectators. (Concerning the visual arts, a cynic might say that art is simply what is found in art galleries.) Another issue concerns value judgments. Is beauty in the eye of the beholders Are all interpretations of equal worth or are some critics better qualified than others? Finally, we can ask whether art has a function or is it, for example, essentially sensuous and designed to give pleasure. Does it have a revealing function that serves to show us truths that in some sense lie beyond words?

Religion

Is there some further or higher reality above this one? If so, how could we know about it? What if anything, can be understood by the proposition, 'God exists'? Some argue that the apparent order in the universe constitutes prima facie evidence in favor of God's existence. Others point to the fact of suffering as prima facie evidence against it. A different approach is to say that religious belief is a matter of faith rather than reason. What then is faith? Can faith be rational or does religious knowledge lie beyond words? (Can we know something it we cannot put it into words?)

Science

One of the distinguishing features of modern science is its' success. Such success may be thought to result from the use of a specific methodology based on observation and repeatable experiments, but is there really 'a logic' of scientific discovery or is the process essentially irrational?

Science is often said to prove things. It explains phenomena in terms of general laws and principles; but there are in fact, certain philosophical difficulties concerning the status of such laws and principles. Some scientists believe that one day the whole of science will be explicable in terms of a few very basic principles. This view is known as reductionism. An interesting question to ask is, 'How do the human sciences fit into this picture'? Some anti-reductionist thinkers have argued that since human beings are conscious and their actions are purposive our explanations of human behavior will always be different in kind from those of the natural sciences.

History

Many of our judgments are implicitly historical in nature. The only way that we can understand the present is by relating it to the past. This provides the justification for why we study history but can history itself be objective? Some have claimed to discern laws of historical motion that determine what appears to us as the flux of events and they have thus considered history to be a science. Others have seen history as an essentially random process influenced by chance or the unpredictable actions of particular individuals (the Great Men theory).

Morality

What is the difference between a fact and a value? How objective is science, how subjective is morality? (At least one modem philosopher has argued that 'we tend to be too realistic about physics and too subjectivist about ethics'.) Do we have specific moral intuitions that can give us knowledge? Can we deduce moral laws using reason, or is the concept of knowledge inappropriate in morality?

What is the nature of the good life? Is there a single end such as happiness at which all our activities aim or can we ascribe an independent value to other goals such as truth or friendship? Finally, what is the relationship between morality and behavior Are people capable of altruism or are they in some sense always selfish? We often hear about human rights but what exactly are they and from where do they come? Is an individuals' rights absolute or can we sometimes sacrifice them for the greater good? What is a state and why do we need one? Is democracy the best form of government or are there other preferable alternatives - for example, benevolent dictatorship? Are people really free in modern industrial societies, or are they simply tricked into believing that they are free.