Miejsce realizacji: Gmach Główny KUL (GG 243)
Adres: Lublin, Aleje Racławickie 14

If I asked you what you see right now, your answer would be probably like “I see the display of my phone”. Indeed, our common sense tells us that this is true. Speaking more generally, those of us who are not philosophers universally accept two quite natural claims: (a) that things exist whether we see them or not, and (b) that those things are exactly the same as we perceive them. However, upon a closer examination it turns out that these views are impossible to defend.

Let us start with the claim (b). We can give some very simple examples to prove it false. The Moon appears bigger than the Sun but in fact it is quite the contrary. A stick in water looks bent or broken while it is perfectly straight. If I had a coin in my hand, it would appear round for someone in front of me and elliptic for someone sitting on my left or on my right. We have, thus, countless examples proving that (b) has to be rejected. However, the rejection of (b) gets us into big trouble. Why? Because we need to reject as well that we perceive external things. Consider the example of a coin: the first person perceives it as round and the second – as elliptic. However, it seems obvious that the coin cannot have these two contradictory properties at the same time! It means that at least one person perceives something different than the coin. But what on earth is it?

Now let us move to the claim (a): it seems obvious that things exist independently of our perception. I believe that my room – all my books, my computer, the desk I am writing on right now, etc. – still exists when I do not perceive it, for example, when I’m left. However, one does not need to prove (a) false in order to doubt it. For, it is enough to ask: What evidence do you have that this is the case? If I do not perceive a given thing – and by definition I cannot perceive something unperceived – it is clear I cannot prove that it exists. Compare: If I told you there is a pink elephant in your room that no one can see, you would probably say that I have lost my mind. Of course, with regard to my room, you may argue that there are certain regularities: for example, my copy of David Chalmers’ The Conscious Mind is still in the same place now as it was an hour ago when I looked at it for the last time, so it is plausible that it simply was there all that time. However, I still do not have any direct proof for this claim.

The purpose of my classes – a combination of a lecture, a discussion and a workshop – is to demolish your commonsense view on perception. I will present the most powerful arguments that appeared in philosophy in order to undermine your basic beliefs about the way you know the world. We will discuss Descartes, John Locke but also Galileo and modern physicists. We will not find many answers to questions I will ask, but it will help us to express more carefully the commonsense beliefs we previously held.