How does science work?

by Neil Rickert

For the moment, I am presenting this as a question.  It is a question for which I believe I have the answer.  But I will postpone discussing that until future posts.

I am currently watching (for the second time), a TED talk by David Deutsch:

In that video, Deutsch is puzzling about what changed at the time of the scientific revolution.  He correctly points out that people have been making observations and coming up with explanations for thousands of years.  We often describe their explanations as myths.  Something must have changed in what we are doing, that made science possible.

I strongly recommend watching that Deutsch video, though I disagree with its conclusions.

Deutsch’s idea is that the ancients were looking for the wrong kind of explanation, and that modern science has been looking for the right kind of explanation.  For Deutsch, a bad explanation is one that can be easily varied to accomodate new evidence.  A good explanation should be difficult to vary.  However, according to the Quine-Duhem thesis, this problem applies in some manner to all scientific theories.

Is disagree with Deutsch on the role of explanations.  In my opinion, we should treat all scientific explanations as myths.  A scientific explanation is, in some sense, the advertising blurb used in the marketing of a scientific theory.  The explanation is needed, as a way of drawing people’s attention to the science.  But the explanation often oversimplifies and distorts the actual science.

Over the last few days, I have been rereading Laudan’s book:

In that book, Laudan has four fictional philosophers of science discussing their disagreements about their work.  The four are a positivist, a realist, a pragmatist and a relativist.

I presume that Laudan’s main aim is to contrast the relativist’s view with that of the others.  However, what comes across to me, is that the other philosophers also have significant disagreements with one another.  As I read through the discussions, I find that I sometimes agree with one of the participants and sometimes with another.  I perhaps agree least with the positivist, though I do share the positivists view that we should eschew metaphysics.  I think I agree most with the pragmatist.  But there are points where I agree with the realist and points where I agree with the relativist.

Their committee discussions center around some of the same issues that Deutsch discusses in his view:

  • What does it mean to say that science is progressing?
  • What is the significance of the apparent theory-ladenness of data and of the underdeterminination of theories by the data?
  • How do we measure scientific success?
  • Is there an incommensurability between theories (as Kuhn argued)?

Overall, I disagree with every one of the four.  As I see it, they have failed to understand how science works, and their disagreements with one another derive from that failure to understand science.

I still have a post or two coming up on truth and correspondence.  After that, I shall attempt to post something on how science works.  In the meantime, I suggest watching that TED video.

Advertisements

13 Responses to “How does science work?”

  1. As a mathematician I believe, to prove in an abstract and defined system like mathematics and then I will find parallels in the natural world.. like mathematical modeling. The fact is .. these questions are also bugging me for some time.

    Like

  2. Hi Neil,

    Deutsch has worked himself up into an inti-inductionist. His books bang on about this. And, “empiricism … can’t be true” ??? Another of his pets.

    The ‘unseen’ doesn’t come to us (directly) through our senses? Brains don’t ‘perceive’ nerve impulses? Well, this may be true, but that misses the point about empiricism. Deutsch empiricism, as a philosophical epistemology, is really most in opposition to pure rationalism and idealism, and as such is a bit of a straw man when he starts to introduce the physics of the matter into the discussion. The point about empiricism in the physical, scientifically useful sense is that all knowledge does come to use through our physical ‘sense’ experience. That’s the only route in. That we use instruments (including our eyes, ears etc.) to ‘see the unseen’ is just how the physical world turns out to be. What exactly is Deutsch expecting? What magical possibility is he supposing ’empiricism’ as he sees it is requiring?

    I’m being a bit charitable to myself with the use of the term ‘sense’ here, because I don’t only mean through the senses that we associate with nerve impulses – though the senses in this usual sense play a most important role in distinguishing brain-body systems from purely body systems. I need to be clearer in what ’empiricism’ is, in a useful scientific sense.

    It’s worth asking what it would mean to cut off the senses – all ‘senses’ – to prevent any data entering a human. That would have to include a complete detachment of the fetus from the mother’s womb so that no data could enter. Even food is data. In later life it would mean death. In that moment before life of the individual it would mean no life emerging.

    Knowledge, in human terms, is wrapped up in the physical activity of the brain. Yes, the genes we inherit play their part, but they too were formed by the physical experiences of our ancestors. As an individual our first ‘experience’ is the coming together of the genes of our mother and father at conception. That is the package of data that comes to us and starts to form our knowledge as our brain develops, contributing to the formation of the very neurons that the brain becomes. Stop that empirical input and there is no unified human being to acquire any further data that will become knowledge.

    From then on all further knowledge is empirical too. To begin with, until the brain starts to do its work, before the first signs of a brain emerge, our acquisition of the data, that will become some of our knowledge, is a physical experience. When our brains do start to ‘think’ they are still physical systems at work. And even when that final component of empiricisms kicks in, our reasoning capacity, it is still a physical process in action.

    When we talk about knowledge in the traditional philosophical sense we are talking at a high level of abstraction from its physical base; and the problem for philosophy has remained this detachment. Only by thinking about knowledge as physical processes are we able to relate it to the rest of the physical reality that we understand.

    So, empiricism is a physical interaction with the world, most apparently for adult humans being through the senses. And empiricism includes rational thought about our physical experiences; but since thought is a physical process then we can see how, in a naive sense uniformed by later science, that Hume was on the right track.

    Knowledge, in this physical context, is merely the high level human experience of relationships between physical experiences.

    There is nothing specifically distinguishable between one nerve impulse and another. If we break down a complex nerve experience, say looking at a black cat and looking at a black dog, the neuroscientist would be hard pressed to notice any difference if he looked at the nerve impulses leaving the eyes. Because this is only data. And the data only makes sense, becomes knowledge, in a context: the context of the long human life that builds up that context; the life experience.

    Mathematicians and scientists are familiar with this notion of context. “3, 1, 4, 1”. What does that mean? What knowledge have I just given to you? Have I listed the first few digits of pi, or have I given you my credit card PIN? What is a PIN? What is a credit card? Ask any of the great scientists from the early 20th century and they will not be able to deduce knowledge about my PIN, even if I uttered the words “They are the digits of my credit card PIN”. They would not have had the life experience, the empirical acquisition of other appropriate knowledge, through sense data, about PINs, credit cards, electronic funds, electronics, …”. To my aging mother a credit card was a mystical thing, at first, and in many respects probably still is. But she has acquired sufficient knowledge, through experience, to make practical use of one. Context applies not only to the knowledge of deep understanding, but also to the acquisition of sufficient knowledge for practical purposes. From that first combination of genes, packed with their inherent, encoded, ‘innate’ knowledge, our life is an entirely physical experiential one in which we gather data by all means available to us, until our brains start to put all that experience into a growing context, to the extent that we humans label it ‘knowledge’, when viewed from a higher level context.

    So, I think Deutsch is quite wrong to dismiss empiricism the way he does.

    I do agree with his point about good and bad explanations. But in providing his own explanation of explanations it is, by his own standard, a bad explanation, and is therefore Deutsch -wizardry. For he offers no more evidence for it than the evidence for any scientific knowledge. Furthermore, in explaining what he thinks are good explanations he offers examples as evidence much of the scientific knowledge that he has dismissed as unseen. “That’s a good explanation [solar system] … every detail plays a functional role…” Yes, every detail acquired by empirical means. “We know independently of seasons, surfaces tilted …” How do we know that? By empirical means.

    So, Deutsch rejects philosophically simplistic empiricism, but then uses scientific empiricism to make his point. And though I agree that there are good and bad descriptions I think it’s the empiricism that allows us to know the difference – specifically by repeated trials, independent methods, independent results that all point to the same conclusion.

    Deutsch makes a similar mistake in his persistent complaints about induction. Simplistic philosophical induction suffers from the problem of induction, yes. But who expects to acquire certain knowledge from induction? It’s still a valuable tool for coming up with a useful working general conclusion from specific data, until more specific data comes along to change the conclusion. Induction is at the very heart of our working method. Alone it is insufficient, as are all the individual methods that we use. It’s the combination that makes it all work as well as it does. And it’s a weighted system of values. The more methods we use, the more we repeat trials, the more we compare theories, the more independent means of coming to a conclusion, the better weighted an explanation is. That Evolution and God are explanations for how humans came about is not really in doubt. What makes the difference is the inductive inference from vast amounts of experienced data that make Evolution better, and the shear lack of any evidence whatsoever from which to make inductive inferences is what makes the God explanation a bad one.

    Deutsch seems to woo his audience with his reputation for profound ideas. He has become a bit of an authority through that reputation. Which is ironic given his opening salvo against authority.

    Like

    • Deutsch has worked himself up into an inti-inductionist.

      Inductionism is one of the origins myths of epistemology.

      And, “empiricism … can’t be true” ???

      He is talking about empiricism, as it is described in the literature. I have been calling that “traditional empiricism.” Deutsch is right to criticize it. Nevertheless, I consider myself an empiricist.

      The point about empiricism in the physical, scientifically useful sense is that all knowledge does come to use through our physical ‘sense’ experience.

      I dislike that way of talking.

      Knowledge does not come in. There isn’t any knowledge out there that could come in.

      Similarly, I dislike the term “knowledge base” as used in AI and elsewhere in computer science. One thing that is completely clear about a knowledge base, is that it does not have any knowledge.

      What magical possibility is he supposing ‘empiricism’ as he sees it is requiring?

      I’m pretty sure that you are missing the point, somewhere, that you raise such a question.

      Knowledge, in this physical context, is merely the high level human experience of relationships between physical experiences.

      That seems obviously wrong.

      I will be elaborating on my understanding of how science works in a future post, as hinted at in an earlier reply.

      Like

  3. “He is talking about empiricism, as it is described in the literature.”

    Which literature? Philosophy? Fine. But then why apply that restricted use of the term to science? One of the problems is all of this is the unclear definition of terms. Empiricism in old philosophical terms was, like many other terms, uniformed by science. But now that science has given a pretty good account of the brain as a physical system, with no evidence of any other magic at work, restricting the use of the term empiricism to the older philosophical meaning seems limiting. When most scientists speak of empiricism it’s usually in a scientific context.

    You can see the difference here in this debate: http://www.youtube.com/watch?v=e3hpmjf6hhg, where Stephen Law seems intent on using older philosophical examples of problems, claiming they are philosophical, some being empirical, but not specifically scientific. But Peter Atkins is emphasising how science is no more than the application of empiricism in a more rigorous sense.

    Law: “There are non-scientific ways of answering questions … sometimes you can answer a question without doing any empirical science. … Peter tells me he’s got a cat stuffed up his shirt. I go over and have a good old feel. I don’t hear any meows, and I conclude he’s lying. I can pretty conclusively refute his claim that he’s got a cat stuffed up his shirt. When I do that, that’s empirical, based on observation. Is it science? … It depends what you mean by science, maybe.”

    That’s precisely what it does depend on. Science is not something new, in terms of the human capacity to acquire knowledge in some deep sense. Science is only the application of the rigorous use of the physical sensory and mental capacities we have already, by means of using specific methods, and by using instruments (to see the unseen for Deutsch). The empiricism of old philosophy that saw the senses and the mind as distinct things is no longer tenable. The senses are physical, and they feed data to the physical brain, which itself processes data, and stores data in its physical states. The very physical substance of which the brain is made is nothing more than the arrangement of matter in an on-going dynamic process; and as such can be considered data itself. There is no data without physical representation. So much so that some information theorists consider matter itself to be nothing more than data.

    “Knowledge does not come in.”

    I didn’t say it does. Data comes in. The knowledge comes to us, is acquired by us, is created in the human mind, as a relationship between brain states and processes, between the accumulated data, that represent our life experience. This term ‘knowledge’ is a high level term, used by humans that have brains, that expresses this accumulation of relationships between data.

    “There isn’t any knowledge out there that could come in.”

    I agree that there isn’t. There is only data, or patterns in physical reality, as we commonly understand it.

    “One thing that is completely clear about a knowledge base, is that it does not have any knowledge.”

    I agree, when being specific on this point*. A book does not contain knowledge but merely patterns of data, instantiated as states of a physical medium. A book is a system in which the data is laid down in a specific way, is encoded, so that when the author wants to convey some knowledge he has he does it in a form that will invoke that knowledge, hopefully, in the reader.

    But even in the brains of the author and reader there is no ‘knowledge’ to be found if the brains are examined. They too contain only physical states, or processes of transitory states – brains contain data – brains are data. It is only as a whole human brain-body system that has been alive for some time that all the data in the brain, and new data arriving, is related in a way that invokes a response from the brain-body system. The brain-body system labels this accumulation of related data as ‘knowledge’. The brain-body system, the human system, responds physically to this inter-related data, by labelling it ‘knowledge’.

    But then this is a recursive and cumulative process, so that along with this data that is inter-related, are data about terms like ‘label’, ‘knowledge’, ‘thought’, ‘concept’, that have their own acquired context. It’s an entire self-supporting frame of reference that means nothing outside that context. It’s so personal that we take for granted the failure or success of transferring ‘knowledge’. We can all read some work, of a philosopher say, and take quite different things from it, because we are all working within our own context – our own lived and experienced ‘knowledge base’ of data. Sometimes these different and personal contexts can align to some extent, so you can have a ‘school of thought’ where over time members become so used to using the same terms in the same external contexts that the internal personal contexts actually start to become similar – though we don’t know to what extent the similarities are instantiated in actual neurons.

    “I’m pretty sure that you are missing the point, somewhere, that you raise such a question.”

    I was suggesting, through the question, that if Deutsch isn’t requiring some magic (which I take he does not) then his own point about us not having direct experience is pretty trivially uninteresting and does not make a case against empiricism.

    “That [Knowledge, in this physical context, is merely the high level human experience of relationships between physical experiences] seems obviously wrong.”

    If it was obvious there would be no need for philosophy or science on the subject.

    The I found this: “I see knowledge as the causal connections to reality that make it possible to have beliefs about reality.”

    But that seems only a high level description of the relationship between knowledge and beliefs, without saying what beliefs are, in terms of brains.

    From the same post: “Once I have crossed the road, I can discard those beliefs or representations. They are of no further use to me.”

    This is wrong because we do not voluntarily discard our experiences. We appear to have little control over this process. Once you have crossed a road, even though the next similar experience may be different, the former experience will inform your response to crossing the road again. The best that can be said of conscious effort in this context is that we might choose not to make an effort to remember the details of an experience – unlike, say, when learning to drive, or learning to dance, where after some experience we got right we might rehearse it in our mind in order to retain it.

    “I refer to those as ephemeral beliefs. I hold them for only a short period of time, then discard them when I am done.”

    You may attempt to do so consciously, though I’m not sure that active attempt to forget anything is at all helpful, and might even reinforce the memory. But the point about knowledge, and beliefs, is that they are not just the high level philosophical notions that we have become accustomed to – or at least if we want to limit them to those old notions by force of definition we are severely limiting the discussion and excluding empirical data about the brain.

    “In order to do that, I must have an underlying set of capabilities to form these ephemeral beliefs or “just in time” beliefs. I want to use “knowledge” to refer to that underlying set of capabilities, rather than to the beliefs themselves.”

    Now that’s getting awfully close to what I said. The underlying capabilities I am saying consist of the physical brain processes that are both conscious and unconscious that work together, integrated in some as yet not well understood way.

    “I don’t expect that child to have yet developed the capabilities needed to form the beliefs used for safe crossing of that road.”

    He has not yet had sufficient physical experience of that road crossing process in order to establish a brain response process to it to make it an appreciably survivable act.

    “… John Searle discusses learning to ski. He suggests that we might start with some beliefs. But as we learn, we become more skilful. And the beliefs become irrelevant to us. Searle sees us as developing causal connections, such that we no longer need the representations (or beliefs). Searle’s account seems about right to me. I am using “knowledge” to refer to those causal connections that we develop, rather than to the beliefs that became irrelevant.”

    Yes. The physical experience of the brain, as a control system, as a central nervous system (along with the changes in muscle system and other bodily development) ‘learns’, acquires the ‘knowledge’ of how to ski. It builds up a ‘knowledge base’, a means of physically responding to the physical environment by going through physical processes in the brain and the body in real-time.

    * I’m not too concerned about the general use of terms such as ‘knowledge base’. We could be charitable and say that a ‘knowledge base’ is a database that specifically encodes useful knowledge into data in a usefully accessible form. A typical ‘knowledge base’ in the computer software industry will consist of a number of types of online documents that are distinct, yet together allow a lot of knowledge to be easily acquired from the data: Documentation Manual, Tutorials, Forum, Blog, … Or in some cases what is labelled as the ‘knowledge base’ consists of nothing more than an accumulation of answered queries.

    In ‘expert systems’ the ‘knowledge base’ may use more complex algorithms to help the use make decisions that would normally require a more experienced real person. But again this is trivially flexible use of the term ‘knowledge’.

    In all cases (so far) there is no sense in which the system ‘has knowledge’ – at least not to the extent to which we commonly apply it to ourselves. But then, we can argue that since we are physical systems too then we don’t really have ‘knowledge’ in any metaphysical sense that makes ‘knowledge’ different from data.

    Like

  4. The post in question of yours was about knowledge and belief. In it you made statements about how you see that relationship. I pointed out above in my second comment that your description of beliefs and your comment on Searle seem to be consistent with the point I was making here about the physical basis of knowledge, to which you responded in comments here, typically unhelpfully cryptically, “That seems obviously wrong”.

    I also pointed out some detailed disagreement about intentional forgetting of experiences – I don’t think we can forget then intentionally, only not make an effort to remember them by not rehearsing the event. This last point seemed relevant in that the view you express seems to remain based on the philosophical notions of belief and knowledge that assume humans have greater control of the mind than the current understanding of the physical brain would suggest.

    Like

    • The post in question of yours was about knowledge and belief.

      The current post is about how science works. You have not connected your point to the current topic. If it is really about a different post, then comment there.

      I also pointed out some detailed disagreement about intentional forgetting of experiences

      Again, that seems to be related to a different post. Comment there, if you want my reaction.

      Like

  5. The first comment of mine: A response to the Deutsch video and his rejection of empiricism and induction as a significant part of science, to his suggestion of good and bad explanations as being what science is about, and how that relates to knowledge. So, that comment was on topic.

    The second comment of mine: A response to your response. Still about empiricism and the different uses of the term, with an example of how a philosopher and a scientist use it. Plus, an attempt to get at what you mean in your “That seems obviously wrong”, by referring to a previous post of yours that seems to me to be quite close to the physical basis of knowledge in brains that I was offering in this post comment thread. This is still on topic since it relates to the Deutsch video and how science is perceived, and what science is in terms of how it is perceived in the relation to the process of acquiring knowledge. Since I’m asking for clarification on your thoughts here it seemed natural to draw attention here to the specific points you made in the earlier post.

    Like

    • The first comment of mine: A response to the Deutsch video and his rejection of empiricism and induction as a significant part of science, to his suggestion of good and bad explanations as being what science is about, and how that relates to knowledge. So, that comment was on topic.

      Okay. Except for the bit on induction, I did not understand that at all. You seemed to think that Deutsch was rejecting empiricism. My read was that he accepts empiricism in the broad sense (we gain knowledge via our interactions with the world), but disagrees with the traditional account found in philosophy of science.

      You then gave me a youtube video to watch, where you applauded that what Peter Atkins said. I watched the video, and I saw Atkins waffling on saying nothing much of any importance. So I have no idea what your point is.

      Plus, an attempt to get at what you mean in your “That seems obviously wrong”, by referring to a previous post of yours that seems to me to be quite close to the physical basis of knowledge in brains that I was offering in this post comment thread.

      I’ll take back that “obviously wrong” part. For, on rereading that earlier comment, it occurs to me that I don’t even understand what you were saying. I don’t understand what “high level human experience of relationships between physical experiences” could even mean.

      Like

Trackbacks

%d bloggers like this: