Reality: How can we know it exists?
By Mike Holderness Read more: “Special issue: What is reality?“ PHILOSOPHERS are not being rude when they describe the approach most of us take as naive realism. After all, when they cross the street on the way to work, they tend to accept implicitly – as we all do – that there is an external reality that exists independently of our observations of it. But at work, they have to ask: if there is, how can we know? In other words, the question “what exists?” reduces, for what in philosophy passes for practical purposes, to questions such as “what do we mean by ‘know’?” Plato had a go at it 2400 years ago, defining “knowledge” as “justified true belief”. But testing the justification or the truth of beliefs traces back to our perceptions, and we know these can deceive us. Two millennia later, René Descartes decided to work out what he was sure he knew. Legend has it that he climbed into a large stove to do so in warmth and solitude. He emerged declaring that the only thing he knew was that there was something that was doubting everything. The logical conclusion of Descartes’s doubt is solipsism, the conviction that one’s own consciousness is all there is. It’s an idea that is difficult to refute. IT IS DIFFICULT TO REFUTE THE IDEA THAT CONSCIOUSNESS IS ALL THERE IS Samuel Johnson’s notoriously bluff riposte to the questioning of the reality of objects – “I refute it thus!”, kicking a stone – holds no philosophical water. As Descartes pointed out a century earlier,