Schools of Thought: Scepticism

The term ‘sceptic‘ is commonly applied to people who are inclined to doubt accepted beliefs or who habitually mistrust people or ideas in general. Because of this, a sceptic is usually characterised as having a healthy and open-minded tendency to test and probe popularly held beliefs. This can be useful, safeguarding against credulity, but it can also be damaging, leading a person to doubt everything without reason. In either case, this common view and definition of scepticism is quite different from its usage in philosophical discussion.

The philosophical sceptic doesn’t claim that we can know nothing – not least because such an argument would be self defeating (one thing we could not know is that we know nothing). Rather, the sceptic challenges our right to make claims to knowledge. We think we know lots of things, but how can we justify any particular claim to knowledge? How can we defend that knowledge? Our supposed knowledge of the world is based on perceptions gained via our sense, and then mediated by our use of reason. But are these perceptions, are our senses not open to error? We can never be sure we aren’t dreaming or hallucinating, for if dreaming is indistinguishable from our waking lives, we can never be certain that something we think to be true is in fact true. Such concerns when taken to the extreme, can lead to demons and brains in vats….

Epistemology is the area of philosophy concerned with knowledge: determining what we know and how we know it and identifying the conditions to be met for something to count as knowledge. Conceived as such, Epistemology can be seen as an attempt to defeat the arguments of the sceptic. However, many believe that subsequent philosophers have been no more successful than Descartes in defeating scepticism. The concern that in the end there is no sure escape from the vat continues to cast a deep shadow over philosophy.