Cogito ergo sum – I think, therefore I am.
Basically, that is the popular answer to the question: can we really ever know something. Can we ever know that something is true without any doubt?
You might say that you know your name is Frank. But in fact you don’t really know that – you just think your name is Frank. You might in fact be completely insane.
There is no absolute proof of that truth without making some serious assumptions. If you are making assumptions, then you don’t know that you are right. Your assumptions might be wrong.
So what can you really know without making assumptions? René Descartes came up with the answer above. He reckons that he knows that he is thinking, therefore he knows that he exists.
Thing is, that he has made the assumption that if he thinks then he exists. I reckon that’s, not quite right. All you can really know is that there are thoughts. You think that they are your thoughts, but you don’t even know that. Everything else could be an illusion – including the fact that in order to have thoughts something must exist.
This blog could be an illusion.