Notes by RBJ on

Positivist Philosophy

by Leszek Kolakowski

Chapter 1An Overall View of Positivism
§1The rule of phenomenalism.
§2The rule of nominalism.
§3Value judgements
§4Unity of the Scientific Method
Chapter 2Positivism Down to David Hume
§1Medieval positivism.
§2Positivist strands in the seventeenth century.
§3The positivism of the enlightenment.
§4David Hume.
§5The destructive consequences of Hume's work.
Chapter 3Auguste Comte: Positivism in the Romantic Age
§1The controversy about Comte.
§3Ideas of social reform.
§4Reform of the Sciences. The law of the Three States.
§5Sociological programme.
§6The religion of humanity.
§7The results of Comte's thought.
Chapter 4Positivism Triumphant
§1Claude Bernard: the native positivism of science.
§2A positivist ethics: John Stuart Mill.
§3Herbert Spencer: evolutionary positivism.
Chapter 5Positivism of the Neo-Romantic or Modernist Age.
§1The place of empirio-criticism in culture.
§2Avenarius: the idea of a scientific philosophy.
§3Avenarius: the critique of experience.
§4Critique of `introjection'. Coordination between the self and the environment.
§5The principle of economy.
§6Ernst Mach.
§7Arguments against empirio-criticism.
Chapter 6Conventionalism: Destruction of the Concept of Fact
§1The leading idea of conventionalism.
§2The impossibility of proving or disproving hypotheses.
§4Ideological consequences of conventionalism.
Chapter 7Pragmatism and Positivism
§1Peirce's positivism.
§2The pragmatic rehabilitation of metaphysics.
§3Other versions of the pragmatic method. Its overall meaning.
Chapter 8Logical Empiricism: A Scientistic Defence of Threatened Civilization
§1The sources of logical empiricism. How it defines itself.
§2Ludwig Wittgenstein.
§3Scientific statements and metaphysics.
§4The programme for reducing all science to physics.
§5The humanities and the world of values.
§6Logical empiricism in Poland.
§7Operational methodology.
§8Idealogical aspects.


The term "positivism" refers not only to a kind of philosophy, but also to a theory of law, a current in literary history, and a way of addressing certain theological questions. Though there may be something common to these kinds of positivism, we are concerned here only with the philosophical variety.

No comprehensive discussion of positivistic philosophers is intended. The philosophers discussed are those whose discussion will help in understanding the ideas, many of whom did not consider themselves positivists. The book begins and ends in an attempt to characterise philosophical positivism as a whole, the first chapter providing an exposition of the most important features of positivism and the last enquiring into "the meaning" of this style of thinking. The main body follows a historical presentation.

Chapter 1 - An Overall View of Positivism

Positivism is "a collection of rules and evaluative criteria referring to human knowledge". It tells us what kinds of proposition might count as knowledge of the world and gives norms for what questions are meaningful.

These are the most important of the rules:

§1 the rule of phenomenalism - there is no real difference between 'essence' and 'phenomenon'

§2 the rule of nominalism - "every abstract science is a method of abbreviating the recording of experiences and gives us no extra, independent knowledge in the sense that , via its abstractions, it opens access to empirically inaccessible domains of reality".

§3 the rule that refuses to call value judgements and normative statements knowledge - this is essentially Hume's denial that one can derive an "ought" from an "is".

§4 the belief in the essential unity of the scientific method - exactly in what that unity consists seems a bit variable

All the above need to be taken with a pinch of salt, insofar as they have both extreme and moderate interpretations (and the most moderate verge on being content-free). Different positivists have ranged across the spectrum.

Of course, opponents of positivism will speak as if all positivists adhered to the most extreme interpretations.


Chapter 2 - Positivism Down to David Hume

Many of the elements of positivism can be traced back to antiquity, for example, in the writings of stoics, skeptics and atomists.

§1 Medieval Positivism

Roger Bacon, in the thirteenth century "demanded that controlled experiment be made a condition of any knowledge worthy of the name", and also "believed that the value of knowledge can be measured by the effectiveness of its applications". He also had a tendency to technological utopianism.

Positivistic elements appear in writers opposed to scholasticism at Paris and Oxford in the second quarter of the fourteenth century. Of these the best known is William of Occam immortalised in the radical nominalism of "Occam's razor", which tells us that "we are to include in our conception of the world only so much as the irrefutable testimony of experience obliges us to" (often abbreviated as "entities are not to be multiplied without necessity").

This was an anti-metaphysical doctrine opposing the over-inflated ontology of scholastic metaphysics. Occam separated out the domain of science, which was to be based on observation, from that of faith, which addressed matters inaccessible to observation or demonstration. He considered religious truths to be based on faith, their demonstration through natural theology or metaphysics was impossible and unnecessary. This contributed to the separation of secular matters of all kinds (not merely science) from the influence of the church.

The most radically positivistic medieval philosophy was advanced by the Paris nominalists, notably Jean de Mirecourt and Nicolas d'Autrecourt who affirmed that all knowledge was either logical knowledge reducible to the principle of contradiction, or an account of the facts of immediate experience. This extends to a radical phenomenalism, the concept of substance being regarded as superfluous.

§2 Positivist strands in the seventeenth century

"Galileo founded a conception of science that may be called characteristically positivist, which became dominant in the seventeenth century". A key element of Galileo's scientific method was the abandonment of Aristotelian (teleological?) explanation in favour of purely descriptive mathematical laws. Kolakowski here refers to Galileo's "phenomenalist programme for knowledge" though I'm not convinced that its right to call him a phenomenalist. An active advocate for the new science was Marin Mersenne, whose writings contained the outlines of a phenomenalist physics (though again I suspect that "phenomenalist" is used here rather loosely, he expands "quantitative, mechanistic, anti-metaphysical" which leaves me uncertain as to whether I would call it phenomenalist). Mersenne did have metaphysical (religious) beliefs, but did not consider that these could be justified either rationally or experimentally.

Similar to Mersenne was Gassendi, who attacked metaphysical speculation and rational theology. He considered all knowledge, inevitably, to be imperfect.

Descartes and Leibniz also get mentions here, both having some elements of positivism in their thought, both seeking to avoid "explanations" in terms of "unseen faculties or forces, inaccessible to experimental investigation".

§3 The Positivism of the Enlightenment


Chapter 3 - Auguste Comte: Positivism in the Romantic Age

§3 Ideas of Social Reform.

"Comte's whole doctrine, including the theory of knowledge, becomes intelligible only when grasped as a grandiose project for universal reform, encompassing not only science but all spheres of human life."
Comte's ideas of social reform are based on a conception of history which originates with Saint-Simon (similar in some respects to Joseph de Maistre's philosophy). This conceives history as progressing by passing through successive epochs of two distinct kinds, between which it alternates. The epochs are either "organic" or "critical".

Organic epochs are conservative and stable, individuals have their respective places in society, which is itself considered an entity greater and more important than its individual members.

Critical epochs are times of change, "bent above all on destroying the existing order" in which individualism is important and society is "merely the sum total of separate individuals" having no independent existence or values.

Comte lived in a critical epoch following the French revolution and his ideas were intended to provide the basis for the next organic epoch, the "positive society" of the future. This would involve restoration of some features of feudal society, for example, the separation between secular and spiritual authority. Spiritual authority was however to become scientific rather than religious.

Comte recognised the risk that utopian thinking yields an idealised and unrealisable society and looked to his new science of sociology to ensure that his utopian conceptions were adapted to "the natural and necessary characteristics of social life".

He asserted the existence of a social instinct at least as strong as selfish aspirations, which made possible the harmonious coexistence of human beings. The organic and rational society he envisaged would be organised along scientific lines and would depend upon its members adopting a scientific way of thinking. This scientific way of thinking was to be determined by studying the history of science. From an understanding of the way in which scientific methods have evolved through history one could come to an understanding of how they must be in the future. Comte's understanding comes as the law of the three states.

§4 Reform of the Sciences. The Law of the Three States.

The three states are three stages in the development of the human mind. They are:


Chapter 4 - Positivism Triumphant


Chapter 5 - Positivism of the Neo-Romantic or Modernist Age


Chapter 6 - Conventionalism: Destruction of the Concept of Fact

The Leading Idea of Conventionalism

Kolakowski does not classify the conventionalists as positivists (they did not reject metaphysics), but there are similarities and the conventionalist critique of positivism was significant.

Conventionalism is primarily associated with certain French Physicists and Mathematicians, notably Henri Poincaré(1854-1912), but was anticipated by Mach. Other leading French conventionalists were Pierre Duhem(1861-1916), and Edouard Le Roy(1870-1954) The name is associated with certain problems rather than a philosophical doctrine.

Kolakowski states "The Fundamental Idea" thus:

"certain scientific propositions, erroneously taken for descriptions of the world based on the recording and generalisation of experiments, are in fact artificial creations, and we regard them as true not because we are compelled to do so for empirical reasons, but because they are convenient, useful, or because they have aesthetic appeal."
This is closely associated with the doctrine that empirical evidence under-determines theory, that there will often or always be more than one theory which is consistent with the evidence. From this one further step takes us to the position that our view of the world is conventional.

More constructively Kolakowski says that the primary aim of the French conventionalists was to define the epistemological boundary separating metaphysics from science (without rejecting metaphysics).

The impossibility of proving or disproving hypotheses

From the conventionalists we have the idea that observations are "theory laden" rather than yielding objective data. The results of experiments are interpreted through an existing body of scientific theory, hence the support for scientific law which is derived from experimental observations is tainted by a presumption of the truth of those laws in the interpretation of the experiments.

This is held to undermine the empiricist foundationalism in respect of empirical knowledge, to render verification in terms of sensory data untenable and to undermine scientific induction.

From here one step further leads us to the view that "the theory of physics is a purely man-made construction", that they are true by convention and thence to Le Roy's extreme view that the majority of scientific laws are definitions.


First we note that even Poincar

Ideological consequences of conventionalism

Chapter 7 - Pragmatism and Positivism

Kolakowski is here solely concerned with pragmatism as a "philosophy of life" and its relation with positivist thought. It is noted that "radical positivists" have considered "philosophy of life" as diametrically opposed to their scientific way of thought.

This seems an odd introduction for it is immediately made apparent from the account of Peirce's philosophy which follows that Peirce's philosophy can be related to positivism in other matters than "philosophy of life". In fact I found very little in this chapter which I would have called "philosophy of life". Perhaps the author considers the whole "pragmatic" as constituting this philosophy of life, but still, I have little inkling of what it was that the author was excluding. The following three subsections seem mainly concerned with the philosophy of Peirce, James and Dewey respectively.

§1 Peirce's pragmatism.

"He stressed the need for rigorous method in experiment and was anxious to cure philosophy of its two inveterate vices - purely verbal disputes and practical sterility."

"The sciences have a certain number of methodological rules common to them all: namely rules of clarity, criticism, verifiability and objectivity. Philosophy can achieve scientific status and develop the same empirically tested precision if and only if it will rid itself of meaningless terms and falsely formulated problems."

"The meaning of every judgement consists in its strengthening of a practical rule..."

"Peirce explicitly goes so far as to say that the meaning of a judgement is entirely exhausted by its practical consequences."

Notwithstanding these quotes Kolakowski also says that Peirce did not hold the meaning of a sentence to be its practical consequences, but rather that the practical consequences are a criterion of truth for the sentence.
"Peirce asked that practical effectiveness be treated as a criterion of truth."
"Truth was for him a relation of correspondence between judgements and actual states of affairs."

§2 The pragmatic rehabilitation of metaphysics

This refers to James's brand of pragmatism, which seems to have been more radical than Peirce's (and caused Peirce to discontinue the use of the term later in life). James, it appears, did consider the meaning of a sentence to be its practical consequences, and, holding that "metaphysical" statements (such as that God exists) might have good practical consequences he accepted them as meaningful. (he used the term "metaphysics" in a pejorative sense specifically for certain doctrines which he rejected, so "the pragmatic rehabilitation of metaphysics" he is accused of is not something he would have acknowledged in those words) James accepted that sentences which are potentially useful are meaningful as well as those which are actually useful. Both Peirce and James were opposed to positivism as they understood it.

§3 Other versions of the pragmatic method. Its overall meaning

Dewey brought a collective perspective to the instrumental view of meaning and truth, thereby somewhat reducing the instability of truth. His concern with social values lead him to consider value statements as meaningful in just the same way as factual judgements. Truth then becomes relative to a society rather than an individual.

Chapter 8 - Logical Empiricism: A Scientistic Defence of Threatened Civilization



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