Rationalism - from the Latin ratio, meaning 'reason' - is a point of view that states that reason plays the main role in understanding the world and obtaining knowledge. Whilst rationalism has existed throughout the history of philosophy, it is usually associated specifically with three philosophers during the Renaissance:

1. René Descartes (1596-1650)
2. Gottfried Wilhelm Leibniz (1646-1716)
3. Baruch Spinoza (1632-1677)

All 3 of these philosophers shared the belief that we can best understand the world through logic and reasoning. However, this does not mean that they were uninterested in science and experiment – on the contrary, both rationalists and empiricists were keen on scientific enquiry. This was because they were reacting against centuries-old traditions which tried to base an understanding of the world upon ideas put forward by the 4th century BC Greek philosopher Aristotle and the world view of the Bible. Such an outlook was therefore based on tradition and authority, rather than reason and experiment.

For example, Aristotle believed that

• The earth is the centre of the universe.
• The sun and the planets orbit the earth.
• The stars are fixed to a crystalline sphere and are unchanging and eternal.

It is therefore amazing to think that this view persisted for almost 2,000 years. So, although scientific enquiry has always been around, it was not until the 16th century that our world view actually began to change. That it did so was based on the overthrowing of tradition in favour of rational and scientific investigation.

Below are a list of important dates in the development of the modern scientific and rational view of the world (though you will not be tested on them, they are interesting and put the above comments in context).

Next >>