Comments on Quine's 'Observation Sentences'

When one first comes across a description of an “observation sentence”, it would seem, prima facie, that such a thing doesn't exist.

How does Quine describe them? In the following way:

“... a sentence is an observation sentence if all verdicts on it depend on present sensory stimulation and on no stored information beyond what goes into understanding the sentence.” (From Quine's 1969 paper 'Epistemology naturalised'.)

Firstly, there are indeed sentences which we utter that do depend on “present sensory stimulation”. They also depend on “stored information”.

For a start, they require the stored information about the meaning of words and our memories (amongst many other things).

However, Quine does qualify his definition by the final clause: “beyond what goes into understanding the sentence”.

That means that the two things I mentioned (i.e., knowledge of the meanings of words and memories of, say, the objects and events in the observation) can be classed as “what goes into understanding the sentence”.

So even though these things are included in a Quinian observation sentence, it's still nonetheless the case that the sentence is about a current observation. (It's about what a person is a present experiencing or observing.) Yes, other things are needed in order to understand the sentence (things which came well before the observation). However, that doesn't stop the sentence - or what we utter - being an observation sentence if the content of that sentence is only about a present observation.

(This isn't that unlike Kant's acknowledgement that even the knowledge of a priori statements requires the experience of what words mean, etc. - and that's obviously, in Kant's terms, a posteriori knowledge.)

The sentence

“There is a rabbit running before me.”

is about a current observation. Nonetheless, I require previous knowledge in order to make such a statement. Still, the sentence isn't about that past knowledge (or those past memories or experiences). The sentence is about the rabbit. The past knowledge is simply required to make the statement and understand the observation. It's not the subject of the sentence.

Quine himself talks in terms of “stored information”. He writes:

“The very fact that we have learned the language evinces much storing of information, and of information without which we should be in no position to give verdicts on sentences however observational.” (298)

Quine stresses his position on observation sentences by writing:

“... an observation sentence is one on which all speakers of the language give the same verdict when given the same concurrent stimulation.” (298)

All that accepted, there can still be an argument against Quinian observation sentences. Indeed don't Quine's various arguments for holism automatically work against the existence of genuine observation sentences?

Why Observation Sentences?

The naturalistic or scientific bonus of observation sentences – at least according to Quine - is their inter-subjective nature. (Therefore their scientific nature.) In other words, we've moved beyond the first-person pronoun of the aprioristic epistemologist.

As Quine puts it:

“.... the observation sentences are the sentences on which all members of the community will agree under uniform stimulation.” (299)

If inter-subjectivity is stressed, then we must also have moved beyond experiences, sense-data (in the old style) and other personal mental happenings and be focusing instead on the world (or on objects and events in the world). The very fact that there's an element of communal agreement involved when it comes to observation sentences (with a stress on the word “observation”) means that “subjective sensory states” become less relevant or not relevant at all.

Quine put it this way:

“The old tendency to associate observation sentences with a subjective sensory subject matter is rather ironic when we reflect that observation sentences area also meant to be the intersubjective tribunal of scientific hypotheses.” (299)

This alone seems to lead immediately to not only naturalism; but perhaps also to some form of externalism.

Rabbits - rather the experiences of rabbits - are now given priority. (Or at least it seems that way.) Of course the Cartesian/internalist arrived at rabbits via his experience of rabbits. However, the Quinian still arrives at rabbits from communal agreement on the experience of rabbits. So the experiences of rabbits must still be part of the story. It can be said that we've moved to what Roger Scruton calls (if in a different context) a “first person plural” in that it's the grand “we” that determines the nature of rabbits. No single mind can find the truth on rabbits by doing, say, some kind of Cartesian (or Husserlian) reduction.

Clearly we've moved a long way beyond the “Cartesian subject” here. Yet the Cartesian subject ruled epistemology from Descartes (17^th century) to the 20^th century.

Theories of Consciousness Must be Biological

According to neuroscientist and Nobel laureate Gerald Edelman, consciousness “can only be understood from a biological standpoint, not through physics or computer science or other approaches that ignore the structure of the brain”.

When did consciousness become a (fit) subject for science?

According to the science journalist John Horgan (in his book The End of Science: Facing the Limits of Science in the Twilight of the Scientific Age), it was as recently as 1990 — only 32 years ago! This is how Horgan put his case:

“In 1990, Crick and a young collaborator, Christof Koch, a German-born neuroscientists [] proclaimed in Seminars in the Neurosciences that it was time to make consciousness a subject of empirical investigation.”

Following on from that, it could be said that when consciousness became a subject of science; it then became acceptable subject for (at least some) philosophers. (Or at least for those philosophers with scientific credentials or who had a commitment to a strong science-philosophy relationship.)

The essential — and some would say obvious — point that the molecular biologist, biophysicist and neuroscientist Francis Crick made was that the study of consciousness must be a biological — therefore a scientific — study. That is, it isn’t about “arguing over psychological concepts and definitions” (which is what Crick believed philosophers do); but one of “lots of experiments”.

According to Crick, psychologists (as well as philosophers) have

“treated the brain as a black box, which can be understood in terms merely of inputs and outputs rather than of internal mechanisms”.

So consciousness is all about the brain.

In fact it’s even more specific than that in Crick’s case: it’s all about neurons.

As Horgan puts it, “[n]eurons must be the basis for any model of the mind”.

The biologist, neuroscientist and Nobel laureate Gerald Edelman (1929- 2014) is also said to have held the position that the mind

“can only be understood from a biological standpoint, not through physics or computer science or other approaches that ignore the structure of the brain”.

[Clearly all this chimes in well with the philosopher John Searle’s own “biological theory of consciousness” — see here. That said, the scientists mentioned in this essay will almost certainly have at least some problems with Searle’s philosophical positions on consciousness.]

To demonstrate his point, Edelman put the seemingly extreme position of “functionalists” (such as Marvin Minsky) who “say they can build an intelligent being without paying attention to anatomy”.

Two

There’s a simple reason as to why scientists and even philosophers must now concentrate of the brain when it comes to questions about the mind and consciousness. According to Horgan, it’s

“precisely because philosophical approaches to consciousness have all failed that scientists must focus on the brain”.

Indeed another way of putting that is to say that these philosophical theories of mind and consciousness all failed (if that’s truly the case) because they completely ignored the brain!

Perhaps most philosophers didn’t see the brain as being a fit subject for philosophy — or even for the philosophy of mind. Nonetheless, many 20th century philosophers certainly did utilise the findings of neuroscience; especially from the 1960s onwards.

The obvious reason as to why philosophical theories about consciousness — and perhaps the mind generally — are seen as problematic is that they’re all (according to Francis Crick) “untestable and therefore useless”. Indeed it’s been said that even highly-sophisticated philosophical theories of consciousness are in the same ball park as beliefs about the Holy Ghost. Or as the neurophysiologist and computational neuroscientist Christof Koch (1956-) once put it:

“Why don’t you just say that when you have a brain the Holy Ghost comes down and makes you conscious!”

In fact he said that to the Australian philosopher David Chalmers! Chalmers replied to Koch’s rhetorical question. He argued that a belief in the Holy Ghost is “unnecessarily complicated” and that “it would not accord with his own subjective experience”.

Minsky's Solution to the Problem of Consciousness: Higher-Order Processes

There are philosophers and scientists who believe that “the problem of consciousness” is solved.

One example is Marvin Minsky.

Or, more specifically, in response to John Horgan's claim (in his The End of Science) that there are “those who doubted whether computers could be conscious”, Minsky claimed that “consciousness is a trivial issue”. Moreover, he said: “I've solved it, and I don't understand why people don't listen.” (184)

Minsky's definition of “consciousness” is very simple and very counter-intuitive. Or perhaps it seems that way simply because I've never really heard it before. That is, I've never heard anyone define consciousness is such a specific and peculiar manner.

Horgan says that Minsky's definition includes the idea that consciousness is “merely a type of short-term memory”. Minsky himself says that consciousness is a “low-grade system for keeping records”. And here's where Minsky's Artificial Intelligence comes in. Horgan says that

“computer programmes such as LISP, which have features that allow their processing steps to be retraced” are, according to Minsky, 'extremely conscious'” (184).

Prima facie, in Minsky's account there are two things which are either being correlated with consciousness or which are being said to actually constitute consciousness: memory and what philosophers call “higher-order thoughts”.

It's clear that memory is certainly part of Minsky's picture. After all, he talks about “short-term memory” and “keeping records”.

In a sense, higher-order thoughts (or at least higher-order processes) tie in with the idea of memory in that memories can be about prior thoughts, processes and experiences.

So, yes, computers “keep records” of their previous computations or processes (as do humans). More specifically, programs such as LISP are said to “allow their processing steps to be retraced”. And that, according to Minsky, makes them “extremely conscious”.

The first response to this is to say that memory and higher-order processes are aspects of consciousness. They don't actually constitute consciousness.

In other words, is Minsky making a claim here of numerical identity (or definition)? Is he saying? -

consciousness = memory and higher-order processes (thoughts)

Again, higher-order processes are accompanied by consciousness or occur “within” consciousness. Acts of memory too are part of consciousness. Not consciousness itself.

It may indeed be the case that I'm getting bogged down with metaphors and analogies here in that phrases such as “processes are accompanied by consciousness” and “acts of memory are part of consciousness” may not be conceptually appropriate. They may not even make sense.

Nonetheless, there still seems to be something wrong with saying that consciousness simply is memory or higher-order processes (thoughts).

If we move away from computers here and concentrate on persons or human beings, this would be to say that introspection is consciousness. Many philosophers have indeed stressed the importance of introspection and indeed self-consciousness. Though I don't recall any who've said that introspection is consciousness. Again, I would say that introspection occurs within (forgive the spatial metaphor) consciousness or that it is an aspect of consciousness. Not that it is consciousness.

As for the words “self-consciousness”: that sort of gives the game away. It is, after all, meant to signify consciousness of the self. Thus there are two things: consciousness and the self. That means that self-conscious and consciousness can't be one and the same thing. Or, in other words, it is the self which is aware of consciousness or the self which is aware of the self. Again, the self is something given in (another spatial metaphor!) consciousness.

Quantum Dualism, Quantum Free Will & Quantum Consciousness

John Eccles's Quantum Free Will

Quantum mechanics is so sexy that it even explains free will and, therefore, mind-body dualism. Or at least John Eccles (who won the Noble Prize in 1963) thinks so.

This is how free will actually works and, up to a point, the account is completely scientific/biological in nature.

The first question is: How does the mind or self affect the brain?

Firstly, the story is about the brain itself. More specifically, the story is about how brain-cells fire.

Brain-cells fire “when charged molecules, or ions, accumulate at a synapse, causing it to release neurotransmitters” (John Horgan's The End of Science, page 173).

However, that accumulation of charged molecules (or ions) at the synapse doesn't automatically result in the release of neurotransmitters. It depends. What “triggers the firing of the neuron” depends on something else; not only on the accumulation of ions (molecules).

In this state of molecular accumulation, according to Eccles,

“the ions exist in a quantum superposition of states; in some states the neuron discharges and in others it does not”.

Thus the mind/self must “exert its influence over the brain by 'deciding' which neuron will fire and which will not”.

If all this is utterly physical, can we talk about “deciding” at all? Is it the brain (or the neurons) which decides or the mind/self? Is all this tied to a conscious decision? Is it, indeed, a physical explanation of a mental decision? Indeed Is this a modern version of Descartes' pineal gland explanation of the mind-body problem/relationship?

Another way of putting all that is to ask this question:

Can all these physical things occur (i.e., the accumulation of ions at the synapse and even the “quantum superposition” of physical states) without bringing on board either the mind/self or the notion of a “decision”?

In other words, can we accept this quantum explanation and still leave the mind/self out of the picture? Or is this quantum story part of a theory which successfully explains the interaction of mind/self and brain? (In this case, the self/mind itself fires the neurotransmitters and that interaction itself can be explained in terms of a “quantum superposition” of physical states.)

Despite all that neuroscience (or physical theory), John Eccles still says: “We have no proof of any of this.” (173)

So perhaps what's truly motivating Eccles (as John Horgan suggests) is his aversion to what he calls “cheap materialism”. Indeed Eccles classes himself as a “religious person”. Moreover, he says that

“the very nature of the mind is the same as the nature of life. It's a divine creation".

Roger Penrose's Quantum Consciousness

Whereas as quantum mechanics explains free will for John Eccles and Karl Popper, so it explains consciousness itself for Roger Penrose. In fact the two theories tie together in a vague kind of way.

For Eccles, quantum indeterminism (or the superposition of physical states at the synapses of a neurone) is explained by the “action” of the self or mind. With Penrose, the self is kept out of the picture; though quantum indeterminism is kept in.

More specifically,

“Penrose conjectured that microtubules perform non-deterministic, quasi-quantum computations that somehow give rise to consciousness” (176).

What are microtubules? They're “minute tunnels of protein that serve as a kind of skeleton for most cells, including neurons” (176).

The obvious question is: Why do or would non-deterministic, quasi-quantum computations give rise to consciousness? Is it this argument again? -

i) Quantum indeterminacy is mysterious.

ii) Consciousness is mysterious.

iii) Therefore these things must be related?

Could it simply be that because there's no other answer at present that it's seen that this must be answer? If that were the case, then other outrageous things may be the answer too. Why is this quantum stuff more feasible than ghost stuff or outright dualism?

Independent Properties & Ceteris Paribus Clauses

 

It can be said that a commitment to ceteris paribus clauses is also a commitment to “independent properties” or entities.

One way to argue for that would to be in terms of essences or natural kinds (which capture the essence) in regards to properties or things/objects/entities. Thus, even if peripheral aspects of entity/property X change (or peripheral stuff changes X), if “all things remaining equal”, then the essence of X will remain the same.

There are indeed what some people call “causal islands”: abstract objects such as numbers, propositions, etc. (If you accept such things.) In addition, if an object or a property has an essence, then that object will retain its essence “all other things remaining equal”. In other words, in this language, essences are indeed causal islands. They must also be independent. Indeed you can say that essences are also abstractions (if not exactly abstract objects).

Again, in the causal flux, object/property X will keep its essence.

Does the belief in the aforementioned “self-subsistent” (as it were) entities (or properties) involve an automatic philosophical commitment to (or assumption of) the phrase “all other things being equal”? That is, that property or entity X would have exactly this nature regardless of all else?

It can be said that if you change one thing, then you change everything else too. (As various kinds of monist have argued.) Or, less dramatically, if you change one thing, then you must automatically change other things.

For example, if President Obama had an extra finger, then there would also be many other differences too. Even if President Obama had an extra molecule, many other things would be different. For one, that extra molecule would automatically affect other molecules. And that means that one tiny change (a different molecule) would bring about many other changes.

This means that X is dependent on other things. X will also affect other things.

Finally, surely saying that “X is an independent property” can't mean that X could exist without anything else. Although it can be said that X could exist without some of the things it now coexists with.

(Does all the above work against the various monistic theories - and theories of interdependence - in which no entity or property can ever have a nature apart from – all? - other things?)