Archives For Science, Reason, Reality

Quine – Natural Kinds

October 25, 2012 — 4 Comments

Notes on Quine’s famous paper: Natural Kinds

Quine, Willard Van Orman. 1969. Natural Kinds. in Ontological Relativity and Other Essays: Columbia Univ. Press.

The paper starts with a problem for induction: “What tends to confirm an induction?” He relates Hempel’s puzzle of the non-black non-ravens and Goodman’s puzzle of the grue emeralds to an innate sense we have for similarity and sorting into kinds. First of all, we need to understand projection. The grue problem: this has been difficult for me to get my head around and it seems to have some complex logic problems, not to mention much discussion across the net around its implications and predicates. All emeralds studied before 2013 are green, so induction would suggest that all emeralds are green. Simple enough. However, at time t all emeralds turn blue but we do not know this yet. An emerald that has turned from green to blue is grue. So all emeralds studied after time t in 2013 will be grue and hence blue. The predicate green is projectable, the predicate grue is not, as who is to know that the emeralds are going to change color? Some discussions on this have broadened the context to suggest other precious stones change color in the same fashion creating a precedent and likelihood that emeralds will change color, therefore can you use induction to conclude that all emeralds are grue?

A projectable predicate counts towards the confirmation of all x‘s are z‘s. Quine uses projectability to solve the black raven, non-black non-raven problem. ‘Black’ and ‘raven’ are projectable, though ‘non-black’ and ‘non-raven’ are not. Hence, the raven problem is not an induction problem as induction only runs in the same direction as projectability. However, the proposition ‘all non-black things are non-ravens‘ is still lawlike, as it is logically equivalent to ‘all x are y‘.

“A projectable predicate is one that is true of all and only the things of a kind. What makes Goodman’s example a puzzle, however, is the dubious scientific standing of a general notion of similarity, or of kind.” (p116)

Quine then turns his attention from projectability to the problem of determining a ‘property’ as we need to sort kinds via their common properties. The point of projectability was to first outline how we might have confidence in our inductions about kinds in a temporal setting. He then illustrates how fundamental the notion of similarity or kind is to our thinking, yet how alien it is to logic and set theory. The non-logical roots of similarity and kind are important.

“One part of the problem of induction, the part that asks why there should be regularities in nature at all, can, I think, be dismissed. That there are or have been regularities, for whatever reason, is an established fact of science; and we cannot ask better than that. Why there have been regularities is an obscure question, for it is hard to see what would count as an answer. What does make clear sense is this other part of the problem of induction: why does our innate subjective spacing of qualities accord so well with the functionally relevant groupings in nature as to make our inductions tend to come out right? Why should our subjective spacing of qualities have a special purchase on nature and a lien on the future?” (p126)

Quine turns to Darwin and suggests that people’s innate spacing of qualities is a gene-linked trait, and that successful inductions will have become predominate through natural selection. He asserts that he is not generalising or creating a priori arguments. He wants to demonstrate that the ‘innateness’ he is describing is not an argument against empiricism. Rather than innate ideas (rationalists – continental) he is describing innate capacities (empirical – Darwin). He sees philosophy as continuous with science, with no external vantage point (no foundationalism – Quinean holism). Therefore all scientific findings that are at present plausible can be used a specificity in philosophy as elsewhere.

Important: Kornblith departs from Quine on this point. He asserts that we can survive without our cognitive capacities being accurate; see chpt 1.

He next acknowledges inductions conspicuous failures. He uses the sense-input data we have as humans as an example, primarily color. We are well aware of our sense data limitations, yet in spite of an array of inductive errors made in such a context we have still been successful. This boils down to the human condition whereby our limitations have helped us survive on one hand, i.e. color is helpful at the food gathering level, but on the other are insignificant to such activities as broader theoretical science. So there is a dynamic existence and use of sense data and innate similarity biases. Essentially, it is the achievement of the species to have risen above, using inductive inference, his sensory limitations and sensory space. Induction has allowed a trial and error process of theorizing and therefore has a definite temporal quality/factor that needs to be included in any justification discussion of induction:

“A crude example is the modification of the notion of fish by excluding whales and porpoises. Another taxonomic example is the grouping of kangaroos, opossums, and marsupial mice in a single kind, marsupials, while excluding ordinary mice. By primitive standards the marsupial mouse is more similar to the ordinary mouse than to the kangaroo; by theoretical standards the reverse is true.” (p128)



According the Stanford Encyclopedia, much of epistemology has arisen in defence of, or in opposition to various forms of skepticism.

“For example, rationalists could be viewed as skeptical about the possibility of empirical knowledge while not being skeptical with regard to a priori knowledge and empiricists could be seen as skeptical about the possibility of a priori knowledge but not so with regard to empirical knowledge.”

Restricted forms of skepticism can refer to common philosophical problems such as the problem of other minds or the problem of induction. That is, we cannot have knowledge of any propositions in a particular domain. Skepticism in general, however, refers to questioning the validity of our knowledge in domains in which we commonly accept that we have knowledge. Therefore skepticism questions the notion of foundationalism.


From the Stanford Encyclopedia:

“Foundationalism is a view about the structure of justification or knowledge. The foundationalist’s thesis in short is that all knowledge and justified belief rest ultimately on a foundation of noninferential knowledge or justified belief.”

Epistemic Regress Problem:

Any proposition requires a justification (justified true belief). Any justification in turn requires support. Therefore the justifying of propositions is endless. “… why? why? why? but why? …”

Foundationalism seeks to address this issue by suggesting that there are some basic beliefs that do not need justification, upon which all knowledge is built. This means that some things must be true in and of themselves. (what might Heidegger make of this?)

Empiricist Foundationalism

A priori: independent of experience

A posteriori: dependent on experience or empirical evidence

Three Problems for Foundationalism:

1) Poverty of Foundations;

the foundations aren’t enough to build our knowledge upon. They are too limited. A foundationalist might reply with words to the effect that this is just the way it is, for better or worse.

Descartes used method of radical doubt to arrive at certainty. He was unable to doubt his own existence (cogito). Descartes sought to prove existence of external world on basis of clear and distinct ideas. The Cartesian circle is the result of using clear and distinct ideas to prove the existence of God, and then appeal to God to prove certainty of such ideas.

Ultimately it becomes hard to prove there is such a thing as an external world if we require certain foundations for knowledge.

2) Unjustified Foundations (version 1)
arbitariness of foundations

The foundations themselves don’t have justification. So a foundationalist might try to provide justification. However, by justifying a foundational belief, the foundation is no longer playing its role as it is now the result of a justification from elsewhere. So either: you don’t justify the foundational belief and they are just arbitrary, or you justify and they’re not playing their role any more.

3) Unjustified Foundations (version 2)
BonJour’s dilemma:

For sense experience to justify some kind of belief, the sense experience has to have some form of content. So the question is raised as to whether sense experience involves making a judgment that something is the case, or is it just something that happens to you. Is sense experience a cognitive state? If an experience is a cognitive state, then it is the kind of thing that can provide justification for a belief. But, if it is not a cognitive state, simply a sensation, that does not need to be justified or unjustified, it is not clear how it can actually justify a belief.

Karl Popper rethought the idea of foundationalism being a concrete set of assumptions or beliefs upon which knowledge is built. He related his view metaphorically to a swamp in which pillars or structures are sunk to create foundations. THe swamp implies that the empirical foundation of objective science is nothing absolute. Science and its structure and network of theories are a towering edifice that rises out of a swamp of uncertainty and possibility. The foundations are piers going down into the swamp from above. They do not reach a natural base, rather, they stretch down to the necessary degree to support the edifice of theory above.

Notes from Karl Popper: The Formative Years 1902 – 1945

“What Habermas will eventually try to show is that we become rational by conforming to the true nature of language. The objectivity of reason is restored but in the form of communicative reason. But in his first major work, Knowledge and Human Interests, this idea, though present, is not developed. Here his defense of reason against the pessimism of his predecessors in the Frankfurt school takes the form of a defense of reflection. The enemy of reason is what he calls positivism, by which he understands the view that only genuine knowledge is scientific knowledge. The claim that scientific knowledge is the only knowledge is not itself a scientific claim. It is scientism. Positivism is a refusal to reflect, because to make this identification excludes the possibility of asking how knowledge is possible.” (p163)

So the overarching philosophical question becomes ‘how is knowledge possible?’ (epistemology). This is one key area of the philosophy of Kant. Habermas has taken to linguistics to investigate, adopting structuralism as the foundation of understanding all conscious phenomena. For perspective, it is important to remember here the presence of Habermas’ Marxist interests, and Derrida’s critique of structuralism, that structuralism is not radical but merely a substitute for epistemology and other schools of philosophy. That is, structuralism makes the claim that there is no center to understanding, but structuralism itself becomes the new center.

“For a critical philosopher any adequate conception of knowledge must take account of the ‘subjective conditions of the objectivity of possible knowledge’. We can in a sense form the idea of a mode of knowledge that is not ‘ours’ but we associate a meaning with this idea only to the extent that we can derive it as a limiting concept from a kind of knowledge that is possible ‘for us’.” (p165)

Habermas promotes reflection on two cognitive models of knowledge: knowledge as an instrument, and knowledge as a medium. This brings to light a series of implicit presuppositions of the Kantian critique of knowledge which should be rejected:

1) a normative concept of science
2) the assumption of a complete, fixed, knowing subject
3) the separation of theoretical and practical reason

For Habermas reason is intrinsically practical. This is shown through his focus on linguistics. Our engagement in language games is where reason arises and finds form.

Where does Marx fit in?

Habermas is reacting to scientism and positivism. He is trying to reinstate epistemology, in order that these ‘isms’ do not claim authority over knowledge and the understanding of how knowledge is possible. This is a philosophical goal I believe most serious thinkers should be sympathetic to, in that science has proven itself to be fallible, just as any political system, and via the philosophy of Kuhn, also social and cultural in its paradigmatic operations. It is an illusion to take a ‘scientistic’ approach.

“Marx follows the strategy of detaching the exposition of consciousness in its manifestations from the framework of the philosophy of identity (the identity of thought and being, subject and object). Whereas for Hegel mind or spirit (Geist) is the absolute ground of nature, for Marx it is the other way around. This is not, Habermas claims, coarse materialism. Hegel’s phenomenology is given a materialist interpretation in the sense that the changing forms of consciousness are seen as the reflection of changes in modes of material production. The phenomeno-logical construction of the dialectically unfolding forms of consciousness is reinterpreted by Marx as ‘an encoded representation of the self-production of the species’.” (p166)

Materialism in Marx can be seen as having an equivalent in Habermas’ ordinary language communication. Interestingly, Habermas recognizes Marx’s positivism in approaching ideology as itself a science, in the order of the natural sciences. He does not however take the same view on psychoanalysis. An appropriate area for discussion opens up here with regard to Popper who argues the pseudo-scientific status of psych-analysis and non-scientific status of ideology.

Habermas and Gadamer

“If Gadamer’s account of the conditions of the possibility of understanding is correct, then it is not clear that such a project is even possible. Critical theory as Habermas understands it depends on our being able to give a rational grounding of certain norms. The linguistic, cultural, and historical dependence of all our thought and knowledge, which Gadamer’s hermeneutics seems to imply, would apparently rule out the possibility of such a rational grounding.” (p173)

Habermas enthusiastically endorses certain aspects of Gadamer’s philosophy:

linguisticality of tradition
situatedness of understanding
the in principle translatability of every natural language into every other
the self-reflexive character of ordinary language

“What Habermas does oppose is what he calls the ontological self-understanding of Gadamer’s hermeneutics. This is the claim of hermeneutics to universality, which as we shall see he links to the idea that it is not possible to go behind the understanding of ordinary language.” (p173)

Habermas claims that Gadamer’s hermeneutics is a form of ‘idealism of linguisticality’, that it is unable to deal with the phenomenon of ‘systematically distorted communication’, and, finally, that it does not allow for the rational criticism of tradition. (p173)

“Habermas accepts that ordinary language is a kind of meta-institution on which all social institutions are dependent. This is because social institutions depend on social actions and social actions are constituted in ordinary language communication. However, it is also the case, he thinks, that language is part of a complex that is constituted cojointly by language, labor, and power.” (p174)

For Gadamer, the linguistic component of this complex determines the material practice of life. For Habermas, these extra linguistic factors, power and labor, are equally determinate in the outcome of the material practice of life. The communicative power of language is affected by such ‘real’ factors: modes of production and relations of power. Language is at once the fabric of social consensus and mutual understanding, and, a medium for social domination and power. Gadamer refutes this by observing that power is acknowledged through social consensus. Also, Gadamer cites power and means of production as sources of prejudice and therefore proper objects of hermeneutic reflection. This concedes to Habermas that theses extra linguistic factors are present, whilst maintaining a hierarchical order of the structure of hermeneutic philosophy. He prevents it becoming materialist. For Gadamer, labor and power do not fall outside language and tradition (remembering that tradition is not fixed, but is mutable via each generation).

Habermas argues that there is ‘distorted communication’ when language is used ideologically. There is surface meaning (intended meaning) and ‘true’ meaning. This requires critique, which once done, will reveal ‘true’ meaning. Gadamer points out that there is a false assumption that only intended meaning can be understood. The experience of meaning, for Gadamer, has a broader scope than this. Habermas strengthens his argument by introducing psychoanalysis and critique of ideology. These two fields of criticism reveal systematically distorted communication. This is heavily explored in Habermas’ essay ‘On Hermeneutic’s Claim to Universality.”

At this stage in this narrative of Habermas vs. Gadamer it is clear that Habermas is making a valid point on the nature of language and its relation to the material and social experience of people. However, by invoking psychoanalysis, Habermas takes a mis-step that can be highlighted by Popper’s critique of psychanalysis: namely, that psychoanalysis is purely speculative and creates an invalid power-relation between researcher/philosopher/scientist and participant (remembering that it may yield results in the case of psychotic patients and doctors, but this is not a model for the rest of the world).

“Habermas follows Alfred Lorenzer, who treats psychoanalysis as a form of linguistic analysis. The neurotic’s symptomatic expressions are seen as belonging to a deformed language game that has been privatized and split off from the public language game. By tracing the private language game back to a childhood trauma the analyst seeks to draw up a lexicon whereby expressions in the private language can be translated into expressions in the public language. A meaning which had previously been inaccessible to public communication but which determined the neurotic behavior is now made accessible.” (p176)

To use this psychoanalytic process as a comparison to hermeneutic inquiry is to compare an individual engaged in ordinary language games to a neurotic or psychotic, coupled with placing the academic researcher in a position of power akin to that of the doctor to neurotic patient. This is a contradiction to Habermas’ foundational critique’s of positivism and its form of scientism.

“Hermeneutic understanding we have seen is essentially dialogical in character. The aim of dialogue is reaching an understanding, an agreement, about a subject-matter (Sache). It is clear that the form of communication which takes place between analyst and patient is not that of a dialogue between equals, but a contrived mode of discourse which ‘fulfills experimental conditions’. But the main reason why such a case is supposed to call into question hermeneutics’ claim to universality is that it shows that the meaning of the systematically distorted expressions can only be understood by showing how the systematic distortion comes about. And this requires a theoretical framework which goes beyond hermeneutic understanding. It shows that we are able to transcend the dialogue that, according to Gadamer, we are.” (p176)

The analyst in this argument is as context dependent as anything or anyone else and therefore has no validity as an objective observer of the language games of ordinary people. This is a contradiction to the rejection of positivism.

Habermas promotes an ideal to get around this: the existence of a counterfactual community in which communication is unlimited and free of force. This is essentially positivist. Habermas’ determination to critique prejudice has ironically illuminated the intense presence of his own prejudice. For Gadamer this is fine as prejudice is part of hermeneutic inquiry; it is the state of existence. Habermas does a lot of work to find a position in which he can legitimately critique and deconstruct tradition but finds himself the subject of Gadamer’s reasoning that all understanding is theory-laden and prejudiced.

Philosophy of science is going to be an invaluable tool in analyzing this argument as it is hermeneutics claim (as represented by Gadamer) to universality that Habermas points out leaves no room for criticism in the social or natural sciences. If we are subject to our horizons of prejudice and preconception, how can science or social science critique? Gadamer claims that this state of being is not normative, it just simply is. To what extent would Popper or Kuhn, or even Einstein, agree?

From the Stanford Encyclopedia of Philosophy:

“[…] if a theory is incompatible with possible empirical observations it is scientific; conversely, a theory which is compatible with all such observations, either because, as in the case of Marxism, it has been modified solely to accommodate such observations, or because, as in the case of psychoanalytic theories, it is consistent with all possible observations, is unscientific.”

This is a cold, dis-passionate view to establish a method for critiquing the rise of new sciences and ideologies in the 20th century (and obviously prior centuries as well). It does not assert that what is unscientific may not one day become scientific, nor that an unscientific theory or observation may not be enlightening. Popper is addressing demarcation. To separate out that which is and is not scientific.

Induction and Deduction

Induction according to the Oxford English dictionary is defined as follows: “The process of inferring a general law or principle from the observation of particular instances”. The Stanford On-line Encyclopedia explains that induction is not opposed to deduction. Induction has undergone a semantic/lexical change in meaning through the 20th century. Induction used to refer to simply the inference of a conclusion from a set of instances i.e. A is a white swan, B is a white swan, therefore all swans are white. Induction has been refined to not infer from observation nor particulars and does not lead to general laws or principles.

enumerative induction or universal inference; inference from particular instances:

a1, a2, …, an are all Fs that are also G,

to a general law or principle

All Fs are G.

A weaker form of enumerative induction, singular predictive inference, leads not to a generalization but to a singular prediction:

1. a1, a2, …, an are all Fs that are also G.

2. an+1 is also F.


3. an+1 is also G.

Singular predictive inference also has a more general probabilistic form:

1. The proportion p of observed Fs have also been Gs.

2. a, not yet observed, is an F.


3. The probability that a is G is p.”

taken from the Stanford Encyclopedia

Induction is used to estimate the validity of a set of observations as evidence for a statement/proposition about the whole to which they refer.

Deductive, on the hand, works to establish validity and soundness in an argument/proposition by making statements about whether the premises are true or false. Logic uses deductive reasoning.

The deductive procedure:

a) formal: testing the internal consistency of the theoretical system to see if it involves any contradictions.
b) semi-formal: the axiomatising of the theory to distinguish between its empirical and its logical elements.
c) comparing the new theory with existing theories to determine whether it constitutes an advance upon them. One theory is deemed better than another if it has greater empirical data and greater predictive power than its rival.
d) empirical application of the conclusions derived from the theory to test whether it is true. Corroboration does not equal verification, but does prove validity.

Popper argues that induction is never actually used by the scientist destabilizes the Newtonian/Baconian insistence on the primacy of pure observation. Popper argues that all observation is selective and theory laden and that there are no pure or theory-free observations (a characteristic of Heideggerian thought). Popper inserts falsifiability in induction’s place. Falsifiability is not concerned with the origin or nature of the evidence gathered, as Popper argues it is easy to obtain evidence for any viewpoint. Falsifiability simply requires that the theory or conclusion be testable and be conceivably false. Any corroborative evidence should count scientifically only if it is the result of a genuinely risky prediction. Therefore, Popper’s scientific method takes on the characteristic of refutation. The best way to test is to search for refutation as it is logically impossible to conclusively verify a universal proposition by reference to experience. One falsification refutes the theory. The falsification does not need adjusting (as in the case of Marxism), but rather the theory/universal proposition (characteristic of science).

“[…] while advocating falsifiability as the criterion of demarcation for science, Popper explicitly allows for the fact that in practice a single conflicting or counter-instance is never sufficient methodologically to falsify a theory, and that scientific theories are often retained even though much of the available evidence conflicts with them, or is anomalous with respect to them.” Stanford Encyclopedia

Popper recognizes the very human, problem-solving orientation of science and therefore the importance of intuition, subjectivity and the imagination. It does not matter how a theory is arrived at, but rather how it can be tested and falsified/refuted. This view was endorsed by Einstein:

“There is no logical path leading to [the highly universal laws of science]. They can only be reached by intuition, based upon something like an intellectual love of the objects of experience.” Stanford Encyclopedia

This focus on the human characteristic of the scientific endeavor places special emphasis on the role played by the independent creative imagination in the formulation of theory.

Popper on pseudo-science and the personalities it attracts:

“I found that those of my friends who were admirers of Marx, Freud, and Adler, were impressed by a number of points common to these theories, and especially by their apparent explanatory power. These theories appeared to be able to explain practically everything that happened within the fields to which they referred. The study of any of them seemed to have the effect of an intellectual conversion or revelation, opening your eyes to a new truth hidden from those not yet initiated. Once your eyes were thus opened you saw confirming instances everywhere: the world was full of verifications of the theory. Whatever happened always confirmed it. Thus its truth appeared manifest; and unbelievers were clearly people who did not want to see the manifest truth; who refused to see it, either because it was against their class interest, or because of their repressions which were still ‘un-analysed’ and crying aloud for treatment.” (Popper in Conjectures and Refutations, p35)


“[…] with increasing content, probability decreases, and vice versa; or in other words, that content increases with increasing improbability.” (p 218)

“This trivial fact has the following inescapable consequences; if growth of knowledge means that we operate with theories of increasing content, it must also mean that we operate with theories of decreasing probability … Thus if the aim is the advancement or the growth of knowledge, then a high probability cannot possibly be our aim as well: these two aims are incompatible.” (p218)

“And since a low probability means a high probability of being falsified, it follows that a high degree of falsifiability, or refutability, or testability, is one of the aims of science – in fact, precisely the same aim as a high informative content.” (p219)

Truth and Content: Verisimilitude vs Probability

on the credibility of science:

“We hold that this ideal can be realized, very simply, by recognizing that the rationality of science lies not in its habit of appealing to empirical evidence in support of its dogmas – but solely in the critical approach: in an attitude which of course, involves the critical use, among other arguments, of empirical evidence (especially in refutations).” (p229)

Popper is not interested in theories being secure, certain, or probable. Theories that can be tested for mistakes, in order to learn from said mistakes, and therefore improve are the desirable approaches to science: they allow for falsifiability.

“Thus the very idea of error – and of falsifiability – involves the idea of an objective truth as the standard of which we may fall short.” (p229)

Fallibilism: we can never be completely certain about factual issues.

Scientific Change: Conjecture and Refutation

Conjecture: stage 1 of a two step cycle of scientific change. A conjecture is a hypothesis that describes and explains something in the world/universe. A good conjecture is a bold one that takes many risks.

Refutation: the hypothesis is subjected to critical testing in an attempt to show that it is false.

A new conjecture should not be a reaction to falsification in an attempt to avoid the problems revealed by earlier testing. This would lead to an ad-hoc theory, lacking justification and eventually coherence.

“In the ‘Influence of Darwin’ essay, the obvious justification for tracing the background to Darwin’s innovation is to show how much of an innovation it was. In contrast to over two millennia of philosophical commitment to the priority of fixed forms and permanent ends, of over-arching design and pre-established constraints, and a companion denigration of change, the merely experiential and chance, Darwin’s work marks a momentous shift in point of view regarding reality.” (Browning, p8)

“The new approach in philosophy is itself transitional, in process, today and for the foreseeable future. It is not one, at least in 1910, of providing firm hypotheses, much less final answers, regarding the large philosophical problems it faces.” (p14)

“The Darwinian revolution, Dewey declared, had opened the way for a transformation of ‘the logic of knowledge’.” (P18)

“The new proposals regarding knowledge in the first essay and regarding truth in the second were formulated by Dewey concisely, yet meticulously. A specific case of knowing is an experience that, as such, intends or points to another experience, not itself immediately present, but as one which would become fully and immediately present were certain operations carried out. So understood, a knowing upon which one relies in predicting or attempting to control a future experience may be disappointed and, therefore, assessable as misleading. And the truth of an idea (or judgment, proposition, belief, etc) consists of its ‘effective capacity’ to ‘make good,’ that is, to lead to the completion or achievement to which it points by means of the operations and actions it proposes.” (p18)

Writing about John Dewey’s famous essay “The Influence of Darwinism on Philosophy” in The Influence of Darwin on Philosophy and Other Essays in Contemporary Thought: John Dewey, Larry A. Hickman, Douglas Browning

These thoughts point towards an understanding of reality that is itself transitive. This sounds as if it would be in conflict with historicism, as defined in the early 20th century, and the logical positivists. It sounds resonate of Gadamer and Heidegger.