Four features enumerated by Kolakowski as characteristic of positivism: phenomenalism, nominalism, status of value judgements, unity of science.

Other features which may be present, such as empiricism, scepticism, semantic doctrines (verification, utility, pragmatics), methodology for science and philosophy, foundationalisms.

Scepticism has a long history.

The views of some late medieval philosophers may be said to have elements of positivism in them, and contributed towards the separation of scientific knowledge from metaphysics and a separation of secular from ecclesiastical matters.

According to Kolakowski, "the Enlightenment had a positivism all of its own".

Hume scores well on all of Kolakowski's key features and is therefore considered the first full blooded positivist.

Comte is the founding father of positivism, the first to deliberately formulate a positivist philosopher abd the person who gave the position its name.

My notes on the book by Leszek Kolakowski.

There is no real difference between 'essence' and 'phenomenon'.

"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"

An example of this is Hume's denial that one can derive an "ought" from an "is".

A belief in the essential unity of scientific method. Exactly in what that unity consists seems a bit variable.

Its worth noting that positivism is closely related to empiricism, most positivists are also empiricists. David Hume is for example, considered an arch positivist, though John Locke is not.

Though falling short of pyrrhonean extremes positivists are usually of a sceptical tenor and show moderate to strong scepticism in respect of ontology, meaning and truth. In respect of ontology positivism therefore tends to be nominalistic. In respect of meaning positivists are likely to condemn large areas of philosophy and also parts of science as meaningless. In respect of truth, they will demand new standards of rigour in establishing conjectures.

The sceptical tenor of positivism is usually countered by positive doctrines on how meaning can be made clear, and conclusions can be firmly established. Positivist philosophy therefore often includes scientific methodology, and this is usually normative rather than descriptive, i.e. it describes how science and philosophy should be conducted rather than how they are conducted. Positivists are likely also to advocate the application of scientific method in philosophy, though they may differ on what kind of method is appropriate. Sometimes, as in the case of Hume they advocate that philosophers adopt the methods of empirical science. Sometimes, as in the case of logical positivism, they advocate that philosophy adopt the methods of the a priori sciences (mathematics and logic).

It is usual for positivists to distinguish between a priori, analytic, necessary propositions and a posteriori (or empirical), synthetic, and contingent propositions, sometimes holding that these three dichotomies are coextensive. These may also be said to be exhaustive of the realm of true knowledge and to exclude value judgements, ethics, aesthetics.

Positivists are typically also empiricists, holding that our knowledge of empirical truths comes through (or is founded in) our senses, and that a priori knowledge is derived from some some kernel of primitive logical truths (e.g. follows from the law of contradiction). These doctrines may be called foundationalism in respect of factual and logical truth respectively.

Conventionalist's doctrines asserting that certain kinds of propositions are true in virtue of conventions are often found in positivist philosophy. The most common is the view that statements which are logically true are true as a result of the linguistic conventions which determine the meaning of sentences in the language.

Normative scientific methodology is naturally accompanied by conviction of the essential unity of science. This is present, for example, both in Comte conception of Positive Science and in the Unity of Science movement spawned in the twentieth century by logical positivism. The unity of science may be considered to consist in its being reducible to physics.

The sceptical element of positivist though concerns not merely meaning and truth but also utility. The attempt to give criteria for meaning may become connected with questions of utility or pragmatics, and hence utilitarian or pragmatic philosophers may be considered to fall within the broad sweep of positivist thought. However, the positivist distinction between empirical facts and value statements may be lost in utilitarian or pragmatic theories of meaning or truth.

Ancient and modern scepticism in a nutshell.

There was a great deal of sceptical thought in ancient Greece before scepticism became a self conscious philosophical stance. Here are one or two examples.

Socrates and Plato contributed some significant elements to the development of sceptical thought, without themselves being full-blooded sceptics.

An academic sceptic is one who denies the possibility of knowledge.

A pyrrhonean sceptic is one whose doubts are universal and who therefore makes no claims to knowledge.

Michel de Montaigne, the seventeenth century metaphysical poets, and Bayle.

Positivist philosophy in its broadest sense is a general tendency in philosophy which embraces aspects of the thought of many philosophers including Humean scepticism, the work of Comte (who coined the term), elements of utilitarianism and pragmatism, and logical positivism.

Roger Bacon is relevant both for his sweeping scepticism about the received wisdom of his day and for his advocacy of experimental method.

He identified four causes of ignorance:

1. the example of frail and unsuited authority
2. the influence of custom
3. the opinion of the unlearned crowd (which appears to have included all his contemporaries)
4. the concealment of one's ignorance in a display of apparent wisdom

He believed that the only reliable ways of attaining knowledge were through experiment and geometric deduction, and had almost utopian conceptions of what might be achieved if these methods were universally adopted.

Immortalised by the nominalistic principle known as "Occam's razor":

we are to include in our conception of the world only so much as the irrefutable testimony of experience obliges us to

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 Miercourt 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.

"an attempt to view mankind in its natural, thisworldly, physical and social environment, an attempt to minimise differences among men by a sensationalist theory of knowledge, (every human being comes into the world a tabula rasa 'blank slate'), an attempt to project a life in time freed of chimerical 'wrestling with God', designed to improve the concrete conditions of human existence, to speed up the accumulation of knowledge, to do away with prejudice and barren speculation."

Kolakowski1972 p58

The principle element of the Enlightenment is not so much any systematic thoroughgoing scepticism but the strengthening confidence in reason as opposed to faith in worldly matters. The dogmatic disputes between different Christian sects, often leading to persecution, was provocation to scepticism, and the scientific attitude displaced previous more metaphysical approaches to understanding the world.

A good representative pre-positivist is the mathematician and philosopher D'Alembert.

He sought to eliminate from both science and philosophy (including ethics) the theological and metaphysical.

In modern times ("modern" philosophy is usually considered to have begun with Descartes) the most extreme scepticism has been attributed to David Hume. I will summarise it, as best I understand it, in three tiers.

In its most basic and pervasive form Hume's scepticism is connected with his distinction between "relations between ideas" and "matters of fact" (a precursor of Kants analytic/synthetic distinction). For Hume, only the former (among which are the propositions of mathematics) are intuitively or demonstratively certain, and the contrary of any matter of fact is possible.

The second "tier" adds a caveat to his observation that our knowledge of matters of fact is probable rather than demonstrative. And it is that even if softened to judgements of probability, they remain indemonstrable.

The final tier is that, even though "relations between ideas" may be demonstrable, there remains room for doubt about the truth of them.