Sebastien asked:

What point was Hume trying to make with the missing shade of blue in the Treatise of Human Nature?

Answer by Craig Skinner

The existence of the idea of a missing shade of blue contradicts Hume’s Copy Principle that simple ideas all derive from antecedent simple impressions. But he dismisses this ‘exception’ as unimportant. Why then does he mention it, and, as you say what point is he trying to make.

He deals with the matter in exactly the same way in both the Treatise and, eight years later, in the first Enquiry, so that it is no throwaway line or momentary lapse.

He first argues that all perceptions of the mind can be classed as impressions or ideas. He holds that a simple idea is always copied from an antecedent similar impression.

Almost immediately after saying this, he seems to produce an idea not derived from an impression, ‘one contradictory phenomenon’:

"Suppose… a person… perfectly well acquainted with colours of all kinds, excepting one particular shade of blue… which it has never been his fortune to meet with. Let all the different shades of that colour, except that single one, be plac’d before him, descending gradually from the deepest to the lightest… he will perceive a blank, where that shade is wanting, and will be sensible, that there is a greater distance in that place betwixt the contiguous colours, than in any other… I ask whether ’tis possible for him… to… raise up to himself the idea of that particular shade, tho’ it had never been convey’d to him by his senses?" (Treatise 1.1.1.10).

Yes he can, says Hume, and this ‘may serve as a proof’ that simple ideas are not always derived from an antecedent impression. However ‘this instance is so.. .singular, that ’tis scarce worth our observing, and does not merit that… we shou’d alter our general maxim’.

Over the years the exception has been variously explained away as,

* not really an exception: it depends on sensory experience of other shades of blue; or colours are complex not simple ideas; or the subject perceives it as conceptual content (he perceives ‘missing blue shadily’ as modern ‘adverbial’ accounts of perception have it), not as an image.

* Hume being paradoxical in hopes of better book sales (!)

* Hume being ironic. His declared method is observation/ experiment and the undoable thought experiment (how could I know whether I had or hadn’t previously seen that missing shade?), like the metaphysical speculation he decries, is not to be trusted.

But Hume is clear (and, it seems to me, serious): colours are simple ideas, the subject imagines (has an image of) the missing shade, it is an exception to his Principle; and he also appears to recognize that the instance generalizes to other colours and to other sensory modalities.

To me, the least implausible suggestion, is that Hume uses an exception to emphasize that his Principle is an empirical one. In his terminology, it is not a Relation of Ideas (an a priori truth) which would not necessarily tell us anything about the world, but rather a Matter of Fact (contingent truth) of which, therefore, the contrary is logically possible. He is speaking of a conceivable contradiction, not an actual one. But there again he could just have said this without any elaborate example.

So, Hume’s blue shade is a grey area, just right for scholarly dispute of the storm-in-a-teacup sort.

Craig Skinner at philosophos.org

Charles asked:

Alan Turing in his 1950 paper Computing Machinery and Intelligence (Mind 49: 433-460) posited that to verify the proposition Machines can think one must use an The Imitation Game, instead of trying to (philosophically) define the terms machine or think, since this would only lead one to, reflect so far as possible the normal use of the words, and that therefore this, attitude is dangerous, given that there is a certain amount of semantic alteration in any term over time and therefore no definitive verification or answer to our question, Can machines think?

However, can one make a philosophical case that such statements as x can y are statements of ability, and that therefore the Turing test is not a substitute for philosophical investigation, since this can must be decided in and for itself? Therefore the question to which I would like some advice is, Can statements of known ability, i.e. x can do y, be verified using an imitation test which may confuse like with identical with?

Answer by Jürgen Lawrenz

To solve this question, you only need to look at the way we humans communicate via books, letters, emails, radios etc. The possibilities for hoaxes are unlimited. You can never be sure that the author you are reading actually wrote the book (maybe it was ghost writer or a parodist). In some sectors of society, the fashion for expressing oneself are so pervasive that everyone seems to have the same voice and idiom, e.g. argot or scientific and academic literature. I am sure that any programmer worth his salt could get his computer to write up a perfect imitation of a paper on quantum gravity and maybe even imitate such voicing.

But this ignores the human specificity. When a writer or speaker or actor or singer imposes individuality on their tone of voice, their manner of delivery, their syntax and grammar (not to mention sentence fillers like ‘just’, ‘you know?’, ‘eh’, ‘um’ and so on) they are constitutive of individuality. Such inflections carry their own communicative value and intention, and intuitive creatures are capable of discerning them. The phrase ‘reading between the lines’ or ‘understanding what is not being said’ indicate something of this.

The crux of the matter is, that the book you are reading, the speaker or singer you are hearing on radio, are not in direct communication with you, but at a step removed which permits all sorts of technical intervention. The only means of foolproof evaluation of authenticity is your actual presence, so that you can watch the facial motions, eyes and eyebrows, stance and comportment, when you receive much more than just the words (or the song).

Turing’s proposition about testing for the quality of imitation does not meet these indispensable criteria. This is because he and his cronies misunderstand the nature of both imitation and intelligence. It does not take a very deep understanding of ‘human intelligence’ to know that it cannot be reduced to mechanised mimetic resources. Turing literally grabbed the stick by the wrong end, proceeding from the limitations of imitation to the origination of behaviour. This only succeeds in obscuring the difference which pertains to a living creature’s intelligence, of which the most significant content is the initiation or origination of behaviour. Further, it completely ignores that intelligent learning is mimetic only to a limited degree and on the whole considerably individualised, even among children. Every human being knows without the slightest expenditure of deep thought that the only way of ensuring consistent imitation in a learning environment is drill. People who have been drilled are the counterparts to Turing’s machine intelligence, in that they are not required to be persons, but on the contrary expected to perform a quasi machine-like response to the situations which the drill expects them to master (without necessarily involving the specific form of human intelligence).

I might usefully remind you in this context of the dispute around IQ tests that have erupted upon the realisation that these tests do not measure intelligence, but the skill of passing IQ tests. Students sitting repeatedly for IQ tests gain familiarity and improve their results. The logical conclusion for designers of these tests is that they must either accept that the students’ intelligence quotient rises after repeated exposure, or else that their definition of an IQ rests on a defective appreciation of intelligent adaptitivity. However, the predicament for them is that changing the test immediately changes the definition of an IQ. Therefore tests cannot not reveal the intrinsic IQ of the subjects, as the whole concept of an intrinsic level of intelligence is faulty.

The relevance of these comparisons is clearly, that in both cases a kind of ‘absolute’ criterion is posited – in IQ tests for a reliable measure of intelligence, in Turing’s test for a reliable measure of discernment. Both are stale exercises, because they under-appreciate the resourcefulness of human intelligence.

Much more could be brought into this argument, but if you will carefully think about it, you should come to the conclusion that all such tests possess only the limited value of revealing the extent to which subjects can be made willing to suppress the nature of their authentic intelligence to fit into the mould of a mechanical model. These conditions, moreover, reveal that the designers of Turing tests, IQ tests and others of the same ilk simply misunderstand the nature of philosophy as something which it is not. They seem to believe that philosophy is logic, whereas logic is merely a tool for the achievement of consistency in thinking. They seem to believe that philosophy is basically the hoarding of knowledge, whereas in reality philosophy is intrinsically about understanding the knowledge which we acquire by experience and research. Most importantly, however, such tests are about the suppression of human individuality. They reveal almost nothing intrinsic to human intelligence, but everything about minds trapped in a deterministic framework that seeks to trim down the living impulses from which intelligence arises.

I’ll leave it to you to work out whether the existence of such tests implies prejudicial authoritarian pressure on us to stop thinking as individuals and accept that society is better off when we all behave like robots.

Jürgen Lawrenz at philosophos.org

Pica asked:

If I was annihilated and a mentally/ physically perfect copy of me instantaneously came into existence on the other side of the world, would that be a case of travel faster than the speed of light?

Answer by Craig Skinner

No, it would be a case of a digitized superscan (encoding your structure down to the molecular level) travelling (at light speed of course) to the other side of the world where, in another fancy machine with suitable stocks of chemicals, rather like a 3-D printer, decoding of the scan would produce your duplicate.

It would be easy to delay disintegration of the original (you) until the moment the duplicate was completed, thereby producing the duplicate at the exact moment you are annihilated, as your question specifies.

However, this ‘beam me up Scotty’ scenario has both technical and philosophical problems.

Technical: it is estimated that the energy needed to scan at that level of detail, transmit and reconstitute one human may exceed all the energy in all the stars in the galaxy. So probably forever unfeasible.

Philosophical: the setup is often talked of as teleportation (YOU step into the machine on Earth and, moments later, YOU step out of the machine on Mars). But the reality is different. It would be a case of you stepping into your execution chamber and being no more.

Unless of course the disintegration bit was omitted and you and your duplicate, or duplicates, or duplicates of these duplicates, all lived and worked, allowing you to extend your influence to wherever, or whenever – scans can be stored for years – you like.

But let’s assume the law of the land prohibits original/duplicate coexistence so that if you want to go to and from, say, work on Europa quickly, you must accept that, for the first journey you die but a duplicate, considered to be you by everybody including the duplicate itself, does duty for you. Of course this new you in turn dies when the journey home occurs, and so on for every trip.

Would you accept this setup as convenient long-distance travel, or find it as attractive as the gas chamber ?

It depends on whether you think identity or psychological continuity (PC) is more important.

Of course, they normally go together. Indeed, PC (memory) is a key feature of your identity. But they can come apart. For instance, if due to brain damage, you enter a persistent vegetative state, then PC, indeed consciousness, is gone. But we dont then say that YOU dont exist. No, your identity remains, and we say that, sadly, you are in a PVS. Many people think that such a life is not worth living, suggesting that they value PC more than identity.

And, of course, in duplication, PC is preserved whilst identity is destroyed. So if you think that PC is a most valuable feature of human life (even if identity is destroyed) whereas identity without PC is less valuable (as in PVS), then you would be happy to step into the machine.

Would you prefer to enter a PVS (preserving your identity) or to die (destroying your identity) and be replaced by a duplicate that has all your treasured memories, future plans and relationships. Most of us would jump at the latter possibility. But, of course, many of us would prefer just to die full stop than enter a PVS.

I would be reluctant to step into the teleporter and say goodbye, letting my duplicate take over my life.

All of this assumes

1. That a molecularly exact copy of me couldnt be a zombie.
2. That I dont have an immaterial (substantial) soul, a la Descartes.

But these are points for another occasion.

Craig Skinner at philosophos.org

Answer by Shaun Williamson

No it wouldn’t. To travel you must be a material body which starts in one place and arrives at another place by moving through space.

It is possible for something to move faster than the speed of light as long as it isn’t a material body. For example suppose I point a laser at the moon. It makes a spot of light of the surface of the moon. I swing the laser pointer from side to side. If I do it quickly enough the spot of light would move across the surface of the moon faster than the speed of light. However this doesn’t violate relativity because no material bodies are moving faster than the speed of light.

You might also like to read about ‘Spooky action at a distance’ where a quantum property of an atomic particle can be transmitted instantaneously to another particle with which it is entangled over any distance (billions of miles). Again this does not violate relativity because no movement of matter is involved.

Shaun Williamson developed the Ask a Philosopher cgi script question.pl. He did his postgraduate studies on the philosophy of Wittgenstein.

Jonathan asked:

Am I here?

Answer by Helier Robinson

Yes, of course. If you were not you could not ask the question.

Helier Robinson is Emeritus Professor in Philosophy, University of Guelph. His books are available from http://SharebooksPublishing.com.

Answer by Geoffrey Klempner

The first thing we need to establish is who is asking the question and also who is being asked.

It seems absurd to ask myself this question. If I ask a question, or do anything, then it necessarily follows that I exist. Descartes says something along those lines. And if I exist, I must be somewhere, mustn’t I? But then again, strictly according to Descartes’ mind-body dualism, although my body has spatial properties and is therefore located in space, my mind has no spatial properties and therefore cannot ‘be’ anywhere in particular. (Nor would it be correct to say that it is ‘everywhere’, in the sense that space or gravity is everywhere.) For an ‘I’ which is metaphysically distinct from body, there is no ‘here’. What there is, is only the mysterious physical/ metaphysical link that enables mind-body interaction, which for obscure reasons Descartes believed to occur in the pineal gland.

For any variety of physicalist, on the other hand, the answer is necessarily, Yes. It is always true that I am here. To be the kind of entity that is capable of being ‘I’ is necessarily to be located in space. But then again, why should it be necessary that I am here and not also there? Suppose I have a perfect double on twin earth. As I type these words, so does my twin earth double. Are we two or one? Would it be so absurd to say that, rather than it being the case that there are two versions of GK, the entity referred to (that I refer to myself as) ‘GK’ exists in two places simultaneously? In that scenario, ‘I am here’ is false, when understood in the sense of, ‘I am here but not there.’

But you are asking this question of me. How do I know that you exist? Maybe the words were caused by a cosmic accident, a highly improbable but nevertheless logically conceivable sequence of web server errors that caused the Ask a Philosopher form to be submitted and delivered to the Ask a Philosopher mailbox with just that sequence of characters.

Or more likely, between the time when you submitted the form, and I replied, you passed away. You are no longer here. That’s something I could find out, but right now I don’t know the answer to that question.

http://www.philosophypathways.com/vita.html

Anon asked:

On omniscience and immutability. I’m looking at the problem posed by Kretzmann among others. In essence, if God is immutable then then how can he know today is Friday and tomorrow know that today is Saturday as this would mean that he’s subject to change to know one thing to day and another thing tomorrow etc. I am puzzled by few things:

Thanks for your help with this.

Answer by Peter Jones

It seems to me that you are correct. It would make no sense to say that God is immutable and yet knows what time it is. It must always be Now. Or perhaps Never. It would also make no sense to say that He experiences time’s passing, or, come to that, anything at all except perhaps His own presence in what Meister Eckhart calls the ‘Perennial Now’. But then, if God is omniscient, He must experience the passing of time, just as we do, in fact exactly and precisely as we do, right now, for otherwise a human being could know things that God cannot. There is only one solution. We are God, in His mode as a myriad of unenlightened centres of experience in an unreal world of time and space, regret and shame.

So, on this analysis God cannot experience time and yet must experience time. This would be the reason why Lao Tsu says, ‘true words seem paradoxical’. They would only seem so since this seeming contradiction can be resolved. Nagarjuna would reject both views as being one-sided and thus false.

If there is a real dilemma here, as you assume, then it will certainly rest on an assumption. In philosophy they always do. It would be a rule. But it would not be an assumption that in order to know something, really know it, we must ‘have experience of it’. According to the logic of how we know things, ‘knowledge by Identity’ would be the only totally secure form of knowledge. At any rate, Aristotle took this view. Second, an immutable entity would not be able to experience, since by our usual meaning an experience would require the passage of time, and because an experience would require a division of this immutable entity into experience-experiencer as the subject and object of the experience. This is three things that would have to exist for this experience, while in His immutable state God would have to be just one. Third, if God is to be worthy of His definition then He must be able to experience regret and shame. He could only do this, however, in the space-time world of Maya and relativity.

Accordingly, the practices of mysticism are designed to bring us to the point where we can leave behind regret and shame by a process of remembering who we are. This would be the Buddha’s path to the cessation of suffering.

Peter Jones at philosophos.org

Fred asked:

Does the argument from illusion show that there are no differences between the visual experiences involved in veridical perception, illusion, and hallucination?

Answer by Helier Robinson

Yes, Fred, definitely. That is the difficulty with the argument: it has never been refuted, but its conclusion is almost universally rejected, irrationally. The conclusion is that all visual (indeed, perceptual) experiences are representations of reality, not reality itself. That is, the only explanation of illusions is that they are misrepresentation of reality, not reality itself, because they are contradictions between the senses, or contradictions between perceptions and well-established beliefs; and there are no intrinsic differences between veridical and non-veridical perceptions, in which case all perceptions are representations. This means that empirical objects around us — indeed, the entire empirical world — is a representation of the real world, not itself the real world.

This leads to the question: what is the real world like? There are two answers, ultimately the same: the philosophic answer is that it is metaphysical, the scientific answer is that it is theoretical. You can begin to get a handle on all of this if you ask about the nature of your own body: is it real, or only an image of your metaphysical/ theoretical body?

Helier Robinson is Emeritus Professor in Philosophy, University of Guelph. His books are available from http://SharebooksPublishing.com.