An Argument Against Theory-Ladenness

A van-Frassen ish constructive empiricist argument against theory-ladenness:

1. Theory ladenness states that there is no theory-neutral observation

2. Theories on a CE account are not tested on the basis of observable phenomena but on the basis of unobservables which are inferred from the data (statistics, probability, etc).

3. Therefore, constructive empiricism cannot be theory-laden.

The Theological Roots of Thought Experiments in the Middle Ages

Prompted by a fruitful exchange on the Facebook, here’s some historical notes on the roots of thought experiments.

Perhaps the most important event in the history of thought experiments comes in the surprising form of a condemnation of a specific style of natural philosophy – the Condemnation of 1277, issued by Etienne Templar. This condemnation had as its focus a number of Aristotelian propositions, all of which were taken to impugn on the power of God to do whatever He wanted (so long as it didn’t involve a logical contradiction), which included God’s inability to create multiple and different worlds from the actual world, the necessity of all things that happen in the actual world, and constraints on God’s ability to move the heavens in a rectilinear way.

An immediate consequence of the Condemnation was a focus on God’s power for ‘natural impossibilities’ – events with conditions that were impossible from within the received Aristotelian physics. Out of this focus developed two senses of the hypothetical: one concerned with defending Aristotle, the other with moving past him.

The former can be most clearly illustrated by Albert of Saxony:

‘In the fourteenth century, for example, Albert of Saxony, an influential scholastic arts master and natural philosopher, assumed the truth of the eternity of the world and also the existence of a fixed quantity of matter in the world. From these assumptions, he concluded that over an infinite time, this limited quantity of matter would have to furnish bodies for an infinite number of souls. In the course of an eternal period of time, the same matter might serve as the human body of a number of different souls. On the day of resurrection, however, when every soul receives its own material body, a finite quantity of matter would have to receive an infinite number of souls. This was a heretical state of affairs, because one body – indeed every body – would have to receive more than one soul. Albert’s response to this dilemma was typical for natural philosophers who had to contend with theological restrictions. He explains that “the natural philosopher is not much concerned with this argument because when he assumes the eternity of the world, he denies the resurrection of the dead.” Albert simply dropped the inconvenient theological consequences from his discussion but retained the eternity of the world for the sake of the argument. By such appeals and devices, medieval natural philosophers could assume the truth of almost any condemned proposition, provided that they did not proclaim it to be categorically or philosophically true.’ (Edward Grant, ‘The Foundations of Modern Science in the Middle Ages’, p. 80-81)

The more significant sense of the hypothetical, however, turned on God’s power to do anything short of a logical contradiction. This had the effect of encouraging speculation about the world and the way it could be, even though it was ‘naturally impossible’ given Aristotelian physics. The key point to note here isn’t that Aristotle was overthrown or subverted. By using God’s power as a vehicle for speculative natural philosophy, an important meta-counterfactual began to come into view: that the world could coherently be conceived in non-Aristotelian terms. Counterfactuals ‘according to the imagination’ soon became a hallmark of late medieval thought:

‘Natural philosophers actually devised an expression to epitomize this approach when they referred to such counterfactuals as secundum imaginationem, that is, “according to the imagination. The Condemnation of 1277 played a significant role in generating counterfactuals. Many of the condemned articles compelled the acknowledgement of God’s absolute power to do whatever he pleased short of a logical contradiction. Examples of counterfactuals that were derived from the Condemnation of 1277 include the possibility of other worlds, vacua within and beyond our world, and the possibility that God might move our world with a rectilinear motion. In each of these examples, medieval natural philosophers sought to derive consequences within an assumed framework of Aristotelian physics, even though what they initially assumed was impossible in Aristotle’s system. What emerged were a series of interesting speculations, or, as we might say, thought experiments, in which certain Aristotelian principles were challenged and, to some extent, subverted.’ (p. 147-148)

From these counterfactuals emerged new conceptualizations of the world, many of which would be inherited by the early moderns and which would give impetus to the scientific revolution. By clearing the space for non-Aristotelian concepts of the world to be coherently conceived, the groundwork was laid for the assumptions that would drive the scientific revolution:

‘A significant natural impossibility that derived from the condemnation of 1277 involved Article 49, which made it mandatory after 1277 to concede that God could move the world rectilinearly, despite the vacuum that might be left behind. More than an echo of this imaginary manifestation of God’s absolute power reverberated through the seventeenth century. When Gassendi declared that “it is not the case that if God were to move the World from its present location, that space would follow accordingly and move along with it,” he was using the supernatural motion of the world as a convenient support for his belief in the absolute immobility of infinite space. As spokesman for Isaac Newton, Samuel Clarke (1675-1729), in his dispute with Leibniz, also defended the existence of absolute space when he argued that “if space was nothing but the order of things coexisting [as Leibniz maintained]; it would follow that if God should remove the whole material world entire, with any swiftness whatsoever; yet it would still always continue in the same place.” Finally, the power of counterfactuals is nowhere more impressively illustrated than in the principle of inertia, which Newton proclaimed as the first law of motion in The Mathematical Principles of Natural Philosophy (1687): “Every body continues [or perseveres] in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it.”  In medieval intellectual culture, where observation and experiment played negligible roles, counterfactuals were a powerful tool, because they emphasized metaphysics, logic and theology, the very subjects in which medieval natural philosophers excelled.’ (197)

Humean, All Too Humean

I intended this post to be a bit of reflection on agent causation and free will, but I was led in a more fundamental direction after concluding with Timothy o’Connor that an account of agent causation really depends on the impossibility of a Humean account of causation. This is a rather simple thesis that can be summed up as follows: agent causation (AC) takes as fundamental that causes really do necessitate their effects – let’s call this Real Causality (RC). Humean-ism (H) fundamentally denies that causes necessitate their effects. Therefore, the first step towards an account and defense of agent causation ought to begin with a look at the metaphysics of causation – more specifically, why we shouldn’t take H to be the case.

Tim Maudlin in his excellent volume ‘The Metaphysics Within Physics’ maps out H by way of two doctrines derived from a reading of David Lewis:

‘Doctrine 1 (Separability): The complete physical state of the world is determined by (supervenes on) the intrinsic physical state of each spacetime point (or each pointlike object) and the spatio-temporal relations between those points.’

‘Doctrine 2 (Physical Statism): All facts about the world, including modal and nomological facts, are determined by its physical state alone.’ (p. 51)

Maudlin then takes these ideas to task, drawing arguments against Doctrine 1 from quantum physics. Classical physics was indeed separable – the physical state of the universe is, more or less, determined by spatio-temporal relations, dispositions and properties in space and time. Maudlin spends a fair amount of time doing some pretty fancy math and comes to the conclusion that given quantum theory as a part of a true description of the world (which is a separate but related contention – Maudlin isn’t trying for an instrumentalist or consciousness-based interpretation of quantum theory here), separability cannot be sustained. He arrives here by an exposition of particle systems, spin states and entagled states, which is rather technical.

Doctrine 2 Maudlin takes to be indefensible as well, and I’ll quote him at length here:

‘It matters not whether one starts with Newton, who, in the Principia, simply announces his three laws of motion after giving the definitions of various terms, or whether one turns directly to any contemporary textbook on quantum theory, which will treat, e.g., the Schrodinger equation as a fundamental dynamical principle. Physicists seek laws, announce laws, and use laws, but they do not even attempt to analyze them in terms of the total physical state of the universe or anything else…Unlike reductive analyses of possibility, causality, and chance, reductive analyses of laws are not endorsed by scientific practice.

Indeed, scientific practice seems to preclude such an analysis. As we have seen, physical possibility is easily understood in terms of models of the laws of physics. Let us suppose (and how can one deny it) that every model of a set of laws is a possible way for a world governed by those laws to be. Then we can ask: can two different sets of laws have models with the same physical state? Indeed they can. Minkowski space-time, the space time of Special Relativity, is a model of the field equations of General Relativity (in particular, it is a vacuum solution). So an empty Minkowski space-time is one way the world could be if it is governed by the laws of General Relativity. But is Minkowski space-time a model only of the General Relativity laws? Of course not! One could, for example, postulate that Special Relativity is the complete and accurate account of space-time structure, and produce another theory of gravitation, which would still have the vacuum Minkowski space-time as a model. So under the assumption that no possible world can be governed both by the laws of General Relativity and by a rival theory of gravity, the total physical state of the world cannot always determine the laws. The only way out is either to assert that empty Minkowski space-time must be governed by both sets of laws, since it is a model of both, or (a more likely move) that it can be governed by neither set of laws, since neither is the simplest account of space-time structure adequate to the model (the simplest account is just Special Relativity). But how can one maintain that the General Relativistic laws cannot obtain in a world that is a model of the laws, and hence allowed by them? The necessity of distinguishing the physical possibilities (i.e. the ways the world could be given that a set of laws obtains in the world) from the models of the laws signals a momentous shift from philosophical analyses that follow scientific practice to analyses that dictate it.’ (p. 67-68)

There is no shortage of less physics-based reasons to not be a Humean, however. One might point out that Hume’s conclusions have force only if his empiricism is accepted, and there are many good reasons why that shouldn’t be accepted – modern philosophy is, in fact, partly composed of such rejections (Reid, Sellars, and the rejection of the positivists make up part of this history. The positivists, who claimed that non-analytic statements or statements that go beyond empirical justification are meaningless, are left in a position which doesn’t exactly aid one in the search for the laws of nature. Nor are things such as quarks and their flavors logical constructions out of sense-data). This isn’t to say that a wholesale rejection of Hume is called for – his observation that causation is not empirical is absolutely correct, though not his further conclusion that it doesn’t exist at all, since causation is very real though metaphysical category. But if the foundation for Humean-ism, which is a strict empiricism, isn’t sound, then we have far less reason to accept Humean-ism.

Given this all-too-cursory look at why we might not want to be Humean, what exactly follows? Concerning agent causation, we are left with a good bit of space with which to work, now that the shackles of Humean causation have been loosed – we are free to develop an account of agency and freedom in which agents are real causes of events.

Incommensurability and Private Language

– David Bohm argues in his talk in ‘The Structure of Scientific Theories’ that terms in a given scientific theory only have meaning within the context given by that theory. This can probably be called ‘strong incommensurability’ – no two theories seem to be able to talk to each other.

– What this leaves us with is a kind of private language for science – private theory language. If the terms in a theory have their meaning only within the context of that theory, then it would seem that, as far as theories are concerned, scientists are unable to talk to each other. Given, however, the fact that scientists do talk to each other (and sometimes even about each others theories) there must be a snag somewhere.

– Bohm’s solution (and he later acknowledges that though it looks as if he’s advocating a kind of solipsism, he’s not) is to try and show that until a kind of common language can be adopted, confusions will continue to crop up in theory development. He cites a number of scientific cases from quantum mechanics where confusion abounds. Some familiar examples might be von Neumann, Kepler/Newton, etc.

– I think it’s fair to here identify Bohm to be paying tribute to the positivist tradition (Carnap et al) in his effort to move from ‘private theory language’  to a common kind of language – a project which saw a large reaction in 60’s and 70’s philosophy of science, especially in the area of theory-laden observation, which attacked the idea that there is in fact even neutral sensory data and neutral language to translate a theory from and into.

– Despite significant confusions in science (Bohm is correct to identify this) it seems a bit shaky to assert that this is both something to assert that this confusion is something to be avoided at all costs by adoption of a more neutral language (even though a Wittgensteinian picture of language may be of help here). Such confusions are only a strict problem if they stem only from theories not being able to talk to each other and do nothing to advance science – and quite often, these confusions help to sharpen, clarify and discard theories and concepts and so help science to advance forward.

– An example here that Bohm cites is malaria – which, throughout history, has had many different theories formed about its origin, structure, spreading, etc. Bohm notes that every different theory here is incommensurable – theorized causes ranged from bad air, damp air, etc, which all seemed to be confirmed by the data – and that effectively, each theory had nothing in common other than the fact that each dealt with malaria.

– In rebuttal, Robert Causey argues that far from demonstrating strong incommensurability, this merely shows that some theories are harder to falsify and some easy to confirm. The current (correct) theory of malaria makes sense of the same data as earlier, more primitive theories (damp air, bad water, etc) – Causey more or less argues that the history of malaria shows that, far from being incommensurable, these theories dealt with the same problem and the same data. Causey further argues that to show the kind of incommensurablity that Bohm is driving at, Bohm would have to show that (1) the problems dealt with by the different theories really were different problems with only the mere appearance of being the same (2) that the terms used by the different theories really were different and (3) that the differences in these terms and their meanings are different enough to show that the problems the theories were dealing with really were different problems.

– This, though a crude sketch, shows that incommensurability requires a fairly high burden of proof if it’s going to be asserted in as strong of a form that Bohm asserted.

Theory-Ladenness, the Given, Intellectual Passion and Theory Development

Over the last half-century or so, a particular story about philosophy has come under fire. Typically called ‘the myth of the given’, it’s the idea that there is ‘given’ in experience come content upon which we can build our structures of knowledge. Prominent modern criticis include Sellars and Rorty, though criticisms of this story aren’t new to the modern era – Thomas Reid, a contemporary of Hume, directed some pretty serious arguments against ‘the way of ideas’ – the theory that what we perceive directly are ideas, or representations, of the world. Another term common in the early 20th century was ‘sense’datum’, found in the work of Russell and Moore.

The main critiques of this family of ideas, as I see it, come from Sellars, Rorty and Reid. Sellars argues along epistemic lines – our immediately perceived ‘given’ doesn’t justify any other beliefs, contra classical foundationalism, which states (broadly) that a properly functioning noetic structure will, once you trace it all out, have its foundation in a set of immediately justified/perceived beliefs, on the basis of which other beliefs can be formed. Sellars, as stated above, basically says that our apprehension of the given, that is, our immediate perception of the given and the consequent immediate justification, doesn’t justify any further beliefs. Hence, the given cannot serve as a foundation.

Reid, characteristically enough, takes a more common-sense approach, and notes that if we take the way of ideas to be the case, three big problems present themselves: (1) that ideas/given don’t have any explanatory power – he doesn’t see how it’s the case that the perception of ideas does any more explanatory lifting than direct perception of objects – (2) representationalism leads to infinite regress (which has some similarities to Plato’s third-man argument) – and (3) the great skeptical problems of the early moderns – how do I know that my mental representations represent reality accurately? Rorty takes roughly similar lines to Reid’s third point, and from there develops some of his more (in)famous dissolution schemes for the mind. For further reference, the SEP article on Reid is fantastic.

The takeaway from this brief genealogy is this: the idea (haw haw) that we construct our structures of knowledge out of ‘given’ sense-data or ideas (read: empiricism) is, if not untenable, pretty shaky.

A further development of the critique of this philosophical story comes from the philosophy of science: the theory-ladenness of science. This idea states, more or less, that all observation is ‘theory-laden’ or conditioned by prior knowledge – what we see depends on our ‘theories’. The classical example is that of Aristotle and Copernicus looking at the sun – both are looking at the same star, but both see two completely different objects because of their theories. This is a fairly radical idea – this isn’t simply the fact that people interpret data different, but rather the theory-ladenness of science states that there is no neutrel data given. While Sellars’ critique is more epistemic (one could hold to his idea while affirming the existence of the given) theory-ladenness allows no such luxury. Two different observers with two different theories literally see two different objects. For a much fuller and substantially more technical discussion, head here.

Another interesting idea to come ffrom the philosophy of science (which I’ll only mention briefly to save time) is the idea of incommensurability – two different theories cannot map onto each other point-for-point. This thesis is tied to Kuhn and Feyerabend, and generally cashes out to saying that there is no neutral language which different theories can be translted into without some loss of information or meaning.

What’s the payoff here, then? Where does all this leaves us? In a way, I’m not quite sure. We can clearly see that, with the above ideas in hand, that science and theory-development is far from a cold, value-free logical enterprise, a mere accumulation and manipulation of the facts – science and theory-development is a thoroughly human undertaking.

All our scientific research and theory-development takes place within a framework of prior knowledge – this is the theory-ladenness of science. This framework is what enables us to ‘see’, as it were – let’s call this frameowork our ‘eyes’. As we continue to research and develop – less by shutting up and calculating and more by way of instinct-led groping – we make discoveries. Things are discovered which change the framework – which changes our eyes, so to speak. Thus Polanyi:

‘Major discoveries change our interpretive frameowork. Hence it is logically impossible to arrive at these by the continued application of our previous interpretive framework. So we see once more that discovery is creative, in the sense that it is not to be achieved by the diligent performance of any previously known and specifiable procedure. This strengthens our conception of originality.. The application of existing rules can produce valuable surveys, but does not advance the principles of science. We have to cross the logical gap between a problem and its solution by relying on the unspecifiable  impulse of our heuristic passion, and must undergo as we do so a change  of our intellectual personality. Like all ventures  in which we comprehensively dispose of ourselves, such an intentional change of our personality requires a passionate motive to accomplish it. Originality must be passionate.’ (‘Personal Knowledge’, p. 143)

‘From the start of this book [Personal Knowledge] I have had occasion, in various contexts to refer to the overwhelming elation felt by scientists at the moment of discovery, an elation of a kind which only a scientist can feel and which science alone can evoke in him. In the very first chapter I quoted the famous passage in which Kepler announced the discovery of his Third Law: “nothing holds me; I will indulge my sacred fury.” The outbreak of such emotions in the course of discovery is well known, but they are not thought to affect the outcome of discovery. Science is regarded as objectively established in spite of its passionate origins. It should be clear by this time that I dissent from that belief; and I have now come to the point at which I want to deal explicitly with passions in science. I want to show that scientific passions are no mere psychological by-product, but have a logical function which contributes an indispensable element to science. They responded to an essential quality in a scientific statement and may accordingly be said to be right or wrong, depending on whether we acknowledge or deny the presence of that quality in it.

What is this quality? Passions charge objects with emotions, making them repulsive or attractive; positive passions affirm that something is precious. The excitement of the scientist making a discovery is an intellectual passion, telling that something is intellectually precious and, more particularly, that it is precious to science . And this affirmation forms part of science. The words of Kepler which I quoted were not a statement of fact, but neither were they merely a report of Kepler’s personal feelings. They asserted as a valid affirmation of science something else than a fact: namely the scientific interest of certain facts, the facts just discovered by Kepler. They affirmed, indeed, that these facts are immense scientific interest and will be so regarded as long as knowledge lasts. Nor was Kepler deceived in this majestic sentiment. The passing centuries have paid their cumulative tribute to his vision, and so, I believe, will the centuries yet to come.

The function which I attribute here to scientific passion is that of distinguishing between demonstrable facts which are of scientific interest, and those which are not. Only a tiny fraction of all knowable facts are of interest to scientists, and scientific passion serves also as a guide in the assessment of what is of higher and what of lesser interest; what is great in science, and what relatively slight. I want to show that this appreciation depends ultimately on a sense of intellectual beauty; that it is an emotional response which can never be dispassionately defined, any more than we can dispassionately define the beauty of a work of art or the excellence of a noble action.

Scientific discovery reveals new knowledge, but the new vision which accompanies it is not knowledge. It is less than knowledge, for it is a guess; but is more than knowledge, for it is a foreknowledge of things yet unknown and at present perhaps inconceivable. Our vision of the general nature of things is our guide for the interpretation of all future experience. Such guidance is indispensable. Theories of the scientific method which try to explain the establishment of scientific truth by any purely objective formal procedure are doomed to failure. Any process of enquiry unguided by intellectual passions would inevitably spread out into a desert of trivialities. Our vision of reality, to which our sense of scientific beauty responds, must suggest to use the kind of questions that it should be reasonable and interesting to explore. It should recommend the kind of conceptions and empirical relations that are intrinsically plausible and which should therefore be upheld, even when some evidence seems to contradict them, and tell us also, on the other hand, what empirical connections to reject as specious, even though there is evidence for them – evidence that we may as yet be unable to account for on any other assumptions. In fact, without a scale of interest and plausibility based on a vision of reality, nothing can be discovered that is of value to science; and only our grasp of scientific beauty, responding to the evidence of our senses, can evoke this vision.’ (p. 133-135)

Stanley Jaki on Einstein’s Failure

‘The year of that Slovay Congress, was, it is well to recall, the year in which Heisenberg gave his derivation of the principle of indeterminacy concerning measurements in physics. One can therefore in a sense understand Einstein’s tactics in taking on the Copenhagen interpretation at its nerve center, which consisted in the insistence that measurements were inconceivable without someone doing them. Thus it would be argued that the act of measurement, which in one way or another implied pointer readings and therefore a reliance on light quanta, deprived the measurement of absolute precision. Such insistence when elevated into a first principle became equivalent to withdrawing into a citadel. Once confined to measurements within that citadel, one could declare that physical theory was limited to the measurable and therefore had no need of hidden variables. Withdrawal into that citadel also meant the the viewing of anything outside it as unreal. It was such a citadel that Einstein wanted to conquer from within, by trying to devise a thought experiment in which absolute precision was in principle possible. He was bound to fail for the very reason that no measurement is possible without observation. But it did not follow from this that knowledge of reality was equivalent to measuring it with absolute precision. Philosophically the citadel in question did not represent the full range of man’s knowing reality, and it certainly did not represent the full range of modern physics. Einstein’s own theory of relativity was a case in point, and all members of the Copenhagen school could have been forced to admit that it was a telling case.’ (Stanley Jaki, ‘The Road of Science and the Ways to God’, p. 209)

Stanley Jaki on the Copenhagen Theory

‘Whatever the distance of human passions from atomic physics, the real question was whether one’s epistemological attitude was truly general, that is, consistent or not. The impression Bohr gave was that one was to have two kinds of epistemology, one for atomic phenomena, another for everything else, but it was still to be explained whether the understanding, or episteme, could be split in two. On this decisive point Bohr gave at best an impression which was vague and superficial. Staying with superficial impressions means staying on the surface, and this in turn implies the avoidance of deep questions. Typically enough, Bohr completed the final review of his epistemological conflict with Einstein with the remark that “through a singularly fruitful cooperation of a whole generation of physicists we are nearing the goal wheere logical order to a large extent allows us to avoid deep truth.” The most obvious of such deep truths should have been for Bohr the truth of the complementarity of matter and light, waves and particles, atomic stability and indeterminacy. The truth that they were complementary to one another was not a matter of observation, but an inference, and a genuinely metaphysical one, which had no justification in the Copenhagen theory. The truth in question was about the truth of a reality which had complementary aspects. These aspects could really complement one another only if they inhered in a deeper reality, about which Bohr could only be agnostic. A harmony of relations or aspects, complementing one another, such was Bohr’s epistemological message, a message void of reference to the ontological reality of anything harmonious. About the entity which embodied the harmony of relations he was not permitted by his own premises to make any claim and he carefully avoided doing so. In a truly pragmatist way, which he learned from Hoffding, a forerunner of William James, Bohr could speak of fruits, though not of their harmny (which is never a matter of direct observation) and certainly not of the tree which produced the fruits, to say nothing of the soil which supported and nourished the tree. For Bohr the deepest aspect of existence was pragmatic fruitfulness, the rather shallow perspective in which he saw physics itself: “Perhaps the most distinguishing characteristic of the present position of physics is that almost all the ideas which have ever proved to be fruitful in the investigating of nature have found their right place in a common harmony without thereby having diminished their fruitfulness.”

As will be seen shortly, this was not even true of quantum mechanics, a fact which should surprise no one. The really creative elements of quantum mechanics are not the data observed by physicists bu the marvelous ideas formed in their heads. Of those heads few were as impressive as that of Bohr, who for many was a twentieth-century Moses with two flaming horns on his forehead. The horns were the horns of complementarity, but as interpreted by Bohr they could not secure reality to the atomic realm, to say nothing of Moses or Bohr himself. Bohr’s pairs of complementarity resembled pairs of horns from which one could not even infer unambiguously that they were rooted in the same head and thereby truly complementary or that the head itself was real, and even more fundamentally real than the horns themselves.’ (Stanley Jaki, ‘The Road of Science and he Ways to God’, p. 205-206)