Londoner wrote:Yes, negation. You should read it. 'Not' isn't the same as 'not knowing'. If you don't know something, then you cannot say whether it is or is not the case. If I do not know which city is the capital of France, I do not know 'the capital of France is not Calais'Conde Lucanor wrote:Londoner wrote:I beg to differ. If I haven't convinced you, try putting 'not knowing if something is or isn't the case' into a piece of formal logic.
There you go: http://cas2.umkc.edu/philosophy/vade-mecum/3-1.htm The name for the formula "it is not the case that..." is negation.
Once again you forgot about what the point in discussion was. I said logical consequences can be inferred from the initial premise of not knowing something, you said it wasn't possible because it couldn't be translated to formal logic; I just showed you that it can:
It is not the case that we know who shot John F. Kennedy. Therefore, the case remains open.
It is not the case that Yanomami people know cars exist. Therefore, they find no use in gasoline.
It is not the case that philosophers know noumena exists. Therefore, they cannot proclaim its existence.
It is not the case that I know that my senses are reliable. Therefore, I must put reliability on something else.
It seems you have missed the well known faculty of embedding propositions.
Given X= I dislike (), y= Mary thinks (), z= playing poker is fine, then:
[X (y (z))]
[I dislike (Mary thinks (playing poker is fine))]
The verb "to know" can enter in any of such clauses:
[I know that (Mary doesn't know that (Frank knows the answers))]
Londoner wrote:1) Yes! Discussions about phenomena are not discussions within logic. You were the one who introduced the claim your argument was logical.
2) No it really doesn't.
3) If you are discussing the nature of logic, that is not a discussion within logic.
1) So, by your own admission, I'm the one employing logic in this discussion and you don't. Actually that makes a lot of sense and confirms my suspicion.
2)How come Aristotelian logic does stay in the field of logic, despite you saying only formal logic with notational symbols is the one that counts as logic?
3) No, Quine is not discussing the nature of logic, he's discussing the application of logic. Quoting from Quine himself:
"Two main themes run through them. One is the problem of meaning, particularly as involved in the notion of an analytic statement. The other is the notion of ontological commitment, particularly as involved in the problem of universals."
Londoner wrote: I think you may be unclear on what logic is. Remember, in logic you use symbols like 'P' etc. to stand for the propositions, because they represent any proposition.
You are narrowing the scope of logic just to fit your argument. You have reduced all logic to the logical notations of formal logic. Interestingly, that puts outside the field of logic, just to name a few:
1) All of your own statements in this thread.
2) Aristotelian logic.
3) Most of William Quine's essays in "From a Logical Point of View", including his most famous essay. Except for the ones dealing with Mathematical logic, the logical notation symbols are absent.
Londoner wrote:Because science is a part of philosophy; the philosophy of science looks at the context within which science operates.
In other words, because science (according to you) is within the context of philosophy. So then, "within philosophy" is a context, contrary to your initial claim.
Londoner wrote:So, for example, within science we assume the validity of inductive reasoning, whereas philosophy would examine induction.
That is not how it works, but I won't get into that discussion.
Londoner wrote:There is a double negative in that first sentence which makes it hard to follow. I can only repeat:
Noumena' as used by Kant is whatever 'the thing in itself' might be, as distinct from the 'phenomena' which is how it appears to us.
This isn't something I have made up myself; it is what will come up if you Google 'noumenal'. 'The noumenon is a posited object or event that exists without sense or perception'.
Again, I don't think there is any point in my keeping repeating this and you then glossing it next time as 'so what you are saying is...'
Well, Kant may say so, or Google, but what is that Londoner says? You've been caught applying circular reasoning to this noumena/phenomena concept, and it's very unlikely you'll advance any further. By now, I'm pretty much aware that you will not take a clear and firm position on anything. You will just conform to deny statements, resorting to sophistry, even if you have to constantly contradict yourself.
Londoner wrote:Your perceptions are arbitrary in that they depend on the sensory organs humans happen to possess, and the conditions in which they make those perceptions, and the general way you interpret the world.
Three times wrong. First, our sensory organs are not arbitrarily constructed, they have structure and functions, so having them will not make any perception arbitrary, at best just relative to those organs. It's not the same to say that something is relative, than to say is arbitrary. Secondly, perception may be relative to sensory organs, but it would be a mistake to say that ONLY sensory organs participate in perception, as if the origin of sensation were the sensory organ, and nothing else determined the perceptual experience, not even the objects themselves perceived.
Third, is hard to reconcile your claim that nothing we can be certain of, with your statement that "perceptions...depend on the sensory organ humans happen to possess". Sensory organs are, by your accounts, noumena, just the same as grass, and you wouldn't know what and how they are, or that humans posess them. You wouldn't know that perception depends on them, that would be an assumption by faith.
Londoner wrote:So it is not your perception but rather what you call 'reason' that makes you believe it was around 30 million years ago etc.
Reason on the basis of perceptions that are corroborated by independent observations.
Londoner wrote:By looking at a bit of rock now, you cannot tell whether it has been around for all that time, or whether it was created a second ago. We humans create a theory, a structure, to explain things like rocks. This structure (usually) matches the nature of our perceptions. But many theories are possible; maybe God created the universe as it is (including fossils etc.) 6000 years ago - we cannot disprove that through our perceptions. Or we are brains in a vat, our perceptions of 'rocks and what rocks are like' being fed to us by the masters of the matrix.
As I have always stated, our natural, immediate understanding of nature is naive, but even our basic cognitive abilities, combined with the regular patterns of the perceived environment and tools acquired in social life, allow us to grasp in our understanding the underlying order of the world. We know the rock was there before we arrived, it occupies a space, and so on. We can go further and study the rock in more detail, discover things that are not obvious to the naked eye and come up with hypothesis of how it came to be. Of all things in general such hypothesis have been proposed, like gods and supernatural entities being behind all, but most of them were disproved using the tools of science, as it progressed. We know now that the hypothesis of a supernatural entity creating all flora and fauna 6000 years ago does not hold water. It's been such a steady, consistent refutation of such ideas that are the ones we have learned to be more skeptical of.
Londoner wrote:So, we create a theory that fits with perception. Where it doesn't fit in with perception, we tweak it until it does. Having done that, then of course our perceptions are no longer understood as arbitrary, of course they all fit together, because that was the object of the theory.
The problem is that you see the theory as the work of one individual, but theories are constructed socially, even if they are being proposed by one individual. Observations and claims about the world are contrasted among many, allowing more objective accounts. To a higher degree in science, eliminating errors of bias or technical issues in obtaining information.
Londoner wrote:Remember, the 'things in themselves' are supposed to be 'a posited object or event that exists without sense or perception'. But you can only know things via perception. You are claiming to know, via perception, things that by definition are beyond perception.
The statement "object or event that exists without sense or perception" means "without the need of sense or perception", not "excluded of sense or perception". And "via perception" means "through perception". "Via" is the latin word for "way" or "road", so perception is the road, the bridge through which knowledge is acquired. And what are the things we know via perception? Aren't they the "things in themselves"? You're claiming this time that they can't be, even though you have claimed before that we don't know, in other words, that it's possible that the things we know via perception are the "things in themselves". If you're not certain of anything, you can't deny anything.
Londoner wrote:But even one particular piece doesn't. The colour of the same piece of grass will be different under different lights, and to beings with different sorts of eyes. If we see the grass as 'green' we also know that what we are seeing is not a specific property of the grass.
But that only means that the experience of colour in grass will arise from the combined effect of the specific properties of light, the specific properties of the grass leaves to reflect light wavelengths and the specific properties of the eyes with their color-sensitive cone cells. Those are a lot of "things in themselves".
Londoner wrote:'As appropriated'? It is very simple; if we make any claims about the accuracy of our mental representation, then we must be making a comparison with something else, some 'non-mental representation'. Unfortunately, we can never get outside our own heads and do the comparison.
What is "getting outside our heads"? We are not inside our heads, our heads are part of us, residing in a world of things. Our body already give us a connectivity with that world of things through our senses. It's called cognition and it implies recognizing at least our sense organs.
Londoner wrote:And (from your analogy) the fact we are obliged to guess about the real nature of the object by comparing all these different representations, rather than having one single consistent representation does tell us one thing; that no particular representation is reliable. So we do not know what THE TRUTH is, but we do know we are not in possession of it.
The thing is: we are bombarded by sensations. And not only that, we can manipulate them, we move and see the changes of perspective, we feel our own locomotion and how our body responds to our commands or to actions from other bodies. We know the truth that we are in the world, that we can act and transform.
Londoner wrote:That's right, ultimately there is nothing we can be certain of. As I have written before, if there is something you believe it would be impossible to question at some level, I will be interested to hear it.
Do you believe that it's impossible to question the claim that there is nothing we can be certain of? Because that looks like something you are certain of...