Ideas and Thought

Philosophy literally means "love of wisdom" in Greek. This description is true, because those who are interested in philosophy, develop many mental faculties, like critical thinking, rational thought and the ability to use these skills to examine the great questions of our world.

The key thing about philosophy, is that it is more than just a whole collection of knowledge expounded by a collection of mostly dead guys. Philosophy is something that you actually engage in as an activity; that is once you learn some very important principles, aimed at keeping your thinking honest and unpolluted by assumptions, biases, and wishful thinking.

Philosophy also helps you get to the real meaning of things, clarifying your thoughts and forcing you to be succinct and truthful, by exposing ambiguities and forcing you back to first principles. Another important aspect of philosophy, is that evidence and logic is valued. This means, that people who have a fixed and decided world view and cognitive bias toward affirming a particular world view, even when faced with contradictory evidence or information, will not be able to use philosophy adequately to enrich their life. But for the rest, who are willing to question, expose false ideas, beliefs and assumptions; let us charge onward.


Rene DescartesCredit: wikipedia

The theory of knowledge is also called epistemology. Basically epistemology is concerned with "what do we know and how do we know what we know".

Many great philosophers have concerned themselves with epistemological questions. Rene Descartes (1596-1650) famously asked the question, whether there was anything in this world of which "I can be certain".

 Descartes knew that our senses can easily be deceived and our logic is often flawed. This doubt or skepticism, expressed by Descartes, is a very important part of the philosophical process. In this case it also led him to the view that, if he doubted, then he must exist.  The famous words "cogito ergo sum" (I think therefore I am) asserted by Descartes, have become an important foundation in philosophy, as has Descartes skepticism.

In considering what do we know, we may ask questions about whether "love" or "justice" have an objective reality, as Plato (427-347 BCE) does in his dialogues. Aristotle (384-322 BCE) on the other hand, examined those "sorts" of things like "redness", which are within our world of experience, in order to understand universal concepts.

Rationalism and Empiricism

In the field of epistemology there is two main approaches, these being rationalism and empiricism. Rationalists believe, that we can get to the truth by using our mind and intellectual capabilities: especially using deductive logic. René Descartes and his cogito ergo sum, was arrived at, by using reason alone. Such a conclusion is termed a priori. This means that thought processes alone were used, there was no need to get off ones chair and examine or measure anything.

Empiricism however, is a method which uses the senses and experience in the quest for knowledge. John Locke (1632-1704) was a famous British empiricist, who had quite opposing ideas to Descartes. He was of the view, that all our knowledge comes from learning and experience. All babies when born, in Locke's view, were a blank slate or tabula rasa. There were no innate ideas in his opinion, all ideas, even our self-identity comes through the senses. 

 Idealism Realism

Plato cropped Shool of AthensCredit: wikipedia

Plato is regarded as the  father of Idealism, as he believed that two worlds existed. One world was an ideal, perfect, spiritual world, and the other, was the world of appearance and experience.  Bishop George Berkley(1685-1753) was also an idealist. He believed that everything that exists, exists in the mind. The world itself, does not exist outside of our mind. This means that the computer screen infront of you, needs your mind in order to exist. Or in Berkley's words “Esse est percipi”, which means “To be is to be perceived”.

Berkeley opposed Locke's view, that a world of objects exists beyond our senses, which our experiences represent. He wanted to put God in the centre of the universe and so it was his idea, that everything exists because an all-seeing, omnipresent God, perceives it all.

[The premise of Berkeley's argument is however quite flimsy, as he must propose a God existing, which is both omnipresent and all-seeing. As the philosopher David Hume (see below) pointed out, we can claim that God does not exist, without contradicting ourselves, as the notion of God is not based on any sense experience (Empirical) and so we cannot say that God is the cause of anything.]

Aristotle however, is the father of realism. He was of the opinion that reality and objects have an objective reality, which exist independent from the human mind. For example, Aristotle believed the property of "redness" had a concrete reality in space and time and he believed that the way to understand the world was "the diligent and unsparing scrutiny of all observable data." Something did not have to only exist in our minds in order to exist, a flower in the garden exists, whether someone perceives it or not.  

Analytic and Synthetic Statements

David HumeCredit: wikipedia

David Hume (1711-76) was regarded as a great radical in his day. Now he is considered one of the greatest of the Enlightenment philosophers. In his work, Hume applied the empiricist approach. He believed that claims about the world, what he termed "matters of fact" are based on experience. On the other hand, a statement like "triangles have three sides" is a definition, providing no new information. Such statements are either true or false and were viewed by Hume, to be a "relations of ideas."

A statement like "all bachelor's are unmarried" is a matter of fact and this is termed an analytic statement. You cannot deny this statement without contradicting yourself. However, a statement like "Some dogs are white" is called a synthetic proposition. We can deny this statement, without contradicting ourselves.

Hume was also of the view, that all analytic judgments are a priori and all synthetic judgments are a posteriori

A Priori  and a Posteriori

 A fact is a priori, if it is assumed to be true prior to any empirical research. Descartes and his cogito ergo sum falls in to this category, as he did not do any measurements or tests, he used the logic of his mind and probably never left the lounge chair.

Matters of fact that only become known after experience, are termed a posteriori. Such facts are revealed by the experience of the senses i.e. empirical evidence.

An Attempt to Unify Rationalism and Empiricism

Immanuel KantCredit: wikipedia

The philosopher Immanuel Kant (1724-1904) sought to unify Rationalism and Empiricism, using what he called his "Copernican revolution". He claimed both reason and experience contribute to knowledge and make it possible for us to acquire information about how things really are, as opposed to how they seem to us.

Kant also felt that both rationalism and empiricism did not take into consideration, that the human mind is limited and that experience and imagination have certain limitations. Limitations which are both synthetic and a priori. We must also distinguish Kant says, between the phenomena, those things we perceive with out senses and the noumena, the real things; or as Kant termed them "things-in-themselves".

Kant demonstrated that both rationalism and empiricism have limits, as the human mind constructs our experience within certain constraints like space and time. For example, humans generally assume everything has a cause and that this is how the world works. However Kant points out that we impose the concept of causality upon the world, as this is how our mind works.

Adding to the God argument, following on from Berkeley and Hume, Kant rejected all arguments for God's existence, except for the "moral" argument; that is the existence of the human conscience. Or as Kant terms it "the recognition of all duties as divine commands."

(today many philosophers of course would argue that morality and conscience evolved in humans as a survival strategy. Altruism for example favoured group survival)


Another philosophical outlook which crops up when considering epistemology, is pragmatism. This tradition is associated with people like William James (1842-1910), John Dewey (1859 –  1952) and C. S. Peirce (1839-1914). The most simple way to convey this view, is the idea that "whatever works, is likely true.” However, as reality changes, “whatever works” will also change. So what is true, also changes and therefore no one can claim to know the ultimate truth.

And so

We have considered whether knowledge comes from the mind, or the senses. And we have heard that Descartes claimed "I think therefore I am" and concluded, that in simply doubting or thinking, we can know that we exist. Is this true? Can we claim this jump from "I am thinking" to "I exist." Is a self-evident truth? This question however, demonstrates the value of philosophy, that we can start with a question and soon we begin to consider many others.

amicus Plato, sed magis amica veritas