Realisms and Idealisms - Epistemology Video 26
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- čas přidán 25. 04. 2024
- This is video 26 in an introductory course on epistemology, the philosophy of knowledge. In this video, we continue our discussion of perception by looking at several important alternatives to direct realism:
1. The 'indirect realism' of John Locke and René Descartes (1596 - 1650)
2. The 'material idealism' of George Berkeley (1685-1753)
3. The 'formal realism' of Mary Shepherd (1777-1847)
In the next video, we well discuss the transcendental idealism of Immanuel Kant (1724-1804).
Victor Gijsbers teaches philosophy at Leiden University in the Netherlands. You can follow him on mastodon: @victorgijsbers@mastodon.gamedev.place.
This video is part of a lecture series originally recorded for my students during the 2023/2024 spring semester. The entire playlist is here: • Course in Epistemology - Hry
Recently I started reading the problems of philosophy by Russel and your expositions are excellent to help me understand these ideas in more detail. Thanks a lot.
Glad it was helpful!
Here is an interesting thought: what if it is not possible for humans to experience hallucinations that appear as if they are real.
After all, what is the evidence that that our illusory perceptual states are indistinguishable from our veridical states?
If you listen to the reports of people who suffer from hallucinations, they almost always know that they are hallucinating, even though their hallucinations are similar to what a veridical perception of the object of their hallucination would be.
Even with our most ingenious attempts to fool our senses, such as with artificial sweeteners, they are not quite the same as the real thing.
And with so called visual hallucinations, it’s not so much what we see but how we interpret what we see that is at issue.
So, what if this oft repeated philosophical worry about the hallucination that is indiscernible from reality is a fantasy that, given the constitution of humans, is not possible to induce.
I'm impressed with your clear high quality presentation but I am puzzled why you omit the clues that physics and biology give us that indicate any realism cannot be direct. The fact that our sense perceptions are mediated by sense organs and electro chemical signals (which importantntly all have the same nature as each other yet we percieve those relating to different senses radically differently) would seem to rme to rule out direct realism. What am I missing?
Thank you for pointing out Mary Shepherd who had passd me by. Recently I read an article positing (with modelling support) that for perception to evolve successfully it only had to have a logical relation to the "real" world . That is all our precepts are likely to be entirely ideal...but have to be in the same logical relationship as the contents of the world. She seems to have anticipated this "novel" proposal by some 180 years!
Probably because a lot of people defending direct realism also take clues from biology and physics. Here you are defending a peculiar interpretation of natural sciences which goes way beyond the typical agnosticism of scientific approach. It is in fact philosophical in nature and thus a presentation of the philosophical episteme, here about the problem of realism and perception is appropriate since all external data (here from science) will be interpreted through this episteme anyway.
@@Lukainka I'm still puzzled. Why is saying that the optic nerve transmits optical signals and the auditory nerve transmits auditory signals and that these are both electrochemical in nature, a peculiar interpretation of natural science?
This very mediation which a direct realist must admit (because it is experimentally confirmed ie real to them) immediately disproves their position.
The only way I can see to maintain direct realism in the light of our present neuroscientific knowledge is to hold that perception does not arise through the brain. . Which seems to lead to a form of dualism. Is this the move they make?
Hi :) Indeed your description of optical signals isn't an philosophical interpretation. But the conclusion regarding to the philosophical debate is one. As you put it, your description is in fact quite neutral. It doesn't involve per se the sense datum theories from which you seemed to subscribed in your first comment. Somebody like Jon L. Austin criticizes these philosophical misconceptions of the way we perceive things and speak about it.
Thinkers like John McDowell or Hilary Putnam (which is well versed in neurology) would not infere idealism from mainstream neurology, au contraire. I must also mention Wittgenstein who foresaw very early the conceptual entangIement caused by mistaking a philosophical problem for a scientific problem. I couldn't expose here their positions. I can only suggest you to read more realists thinkers in order to better understand why indirect realism is a philosophical conception concerning the relation between the mind and the world rather than a scientific theory which explain how organisms perceived their environment.
Direct realism says that the thing we perceive is the external world, not some intermediate representation in our minds. It does not deny that we may perceive via intermediate physical representations. These may be internal to our bodies (the surface of our retina) or external (the sensor on a camera). But they are not within our mind. Our mind is in contact with the world; how can it not be. It is embedded in the world in the form of our brain.
The idea that we are subject to illusion seems to be based on the idea that perception ought to be a passive thing - we open our eyes and the world floods in and fills our minds with knowledge. But useful perception, the kind that gives us knowledge about the world, is not like a snapshot. Perception is a process of exploration and inference. Vision actually involves firing photons at objects from different angles and seeing which ones come back. It's more like a science experiment.
There are no illusions as such - the biological or mechanical objects that allow us to perceive cannot be in "error" they are just physical objects doing what they do. An infra-red camera used for night vision is not showing us an illusory view of the world, as if the world "ought" to be seen via particular wavelengths of light. There are just different ways of probing the world and we only get the full "picture" by using many different methods.
I don't think we need to add perceivers to the things that exist in berkleys idealism, as they are also perceived, namely by themselves at all times.
Well, it's hard to believe that they are ideas. I'd have to return to Berkeley's text to be sure, but I would be surprised if that's a truly possible interpretation of his writings.
Berkeley could have been an easy victim for theft. If he wasn't looking, he couldn't be certain of what happen with his things.