In this episode I introduce a brief history of scepticism, that is the doubt whether we can have any certain knowledge of the external world. I start with the Greek philosopher Sextus Empiricus who lived in the second century AD. His arguments were taken up and developed by the French Renaissance writer Michel Montaigne (1533-1592). Two French philosophers - Marin Mersenne (1588-1648) and his friend Pierre Gassendi (1592-1655) - rejected this rather defeatist version of scepticism and proposed a more moderate form: it accepts that we can have knowledge of appearances but know nothing about their underlying causes. Modern scepticism, as represented by the philosopher Karl Popper and the physicist Sean Carroll, defends the idea of conjectural knowledge. Science knows about appearances and the underlying causes but this knowledge is conjectural because it is always at the risk of refutation and revision.

Literature:

• Sextus Empiricus, Outlines of Pyrrhonism
• R. H. Popkin, The History of Scepticism (3rd edition 2003)
• N. A. Pinillos, Why We Doubt (OUP 2023)
• F. Weinert, Karl Popper - Professional Philosopher and Public Intellectual (Springer 2022).

This episode introduces the life and influential ideas of William of Ockham (1287-1347). He was a controversial figure in his own time and is famous for his principle, known as Ockham's razor. It is a principle of economy, adopted by many philosophers and scientists, including Cambridge physicist Stephen Hawking. Its modern version recommends to use as few principles as possible to explain a maximum of facts. Ockham himself advised not to make unnecessary assumptions and not to postulate that abstract terms - such as beauty, cathood or humanity, - lead an extra-mental existence of their own in some sort of Platonic realm.

Literature:

This episode is based on my article: 'A razor sharp mind', in The Times Higher Education Supplement (14.03. 1986).

There are informative articles on Ockham in the Stanford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy.

There is the rather common view that the Middle Ages were an age of darkness, ignorance and religious intolerance. But how true is this image? This episode introduces the Middle Ages (1000 AD-1543) as a period of intellectual vitality. It gave rise natural philosophy, which is the precursor of modern science. It accomplished two things. The first task was to make the Bible and Christian religion compatible with the authoritative teachings of Aristotle. This compromise was achieved by two remarkable scholars: Albert the Great (Albertus Magnus, 1200-1280) and Thomas Aquinas (1224-1274). The second task was to recognise Aristotle's errors and develop alternative explanations of the observable events in the natural world. Such alternative explanations were developed by John Buridan (1300-1361) and Nicola Oresme (1325-1382), amongst other scholastic philosophers. Both were followers of William of Ockham's philosophy of nominalism (1287-1347) and the maxim called Ockham's razor.

Literature:

A. C. Crombie: Augustine to Galileo (1959)

J. Hannam: God's Philosophers (2009)

This episode discusses scientific mistakes and blunders which have occurred in the history of science. Mistakes may be based on false information or mistaken assumptions, in which case they are honest mistakes. But if they are based on deliberate misinformation and incompetence, they are downright blunders. We can and should learn from mistakes but blunders are bad news because they have disastrous consequences. If mistakes are based on the wrong assumptions, they are usually be corrected, disproved or dispensed with. Blunders happen because factors external to science (political or religious interference) distort scientific investigations.

Literature:

Robert Youngson, Scientific Blunders. A Brief History of How Wrong Scientists Can Sometimes Be (1998).

Popper's Critical Rationalism consists of two parts: 1) a critical attitude towards science; 2) a critical attitude towards politics. The critical attitude towards science meant that he regarded all scientific knowledge as fallible. No certainty exists in science. All scientific theories are subject to severe tests and are constantly facing the evidence. This is his famous method of falsifiability: all scientific knowledge is fallible. When he applies to it politics, it turns into the fallibility of political leaders and their ideas. It becomes his plea for an open society, in which the rule of law guarantees that political ideas and programmes are subject to rigorous scrutiny to prevent political leaders from doing too much harm. In an open society, the individual enjoys inalienable rights.

Literature:

Popper, K.: Conjectures and Refutations (1963)

Popper, K.: Objective Knowledge (1972)

Popper, K.: The Open Society and Its Enemies (2 volumes, 1966)

Popper, K.: Unended Quest - An Intellectual Biography (1976)

Weinert, F.: Karl Popper - Professional Philosopher and Public Intellectual (2022)

This episode focuses on the Enlightenment in France and Germany. Whilst it shares the basic Enlightenment ideals, there are national characteristics. In France the Enlightenment was shaped by the experience of the Ancien Regime. It is strong opposition to the power of the Catholic Church and Absolute Monarchy. An outstanding achievement of the French Enlightenment is the publication of the Encyclopedia,which was forbidden in 1759.

In Germany, the emphasis is on the meaning of the Enlightenment. What does it mean to be enlightened? Immanuel Kant famously defines the Enlightenment as as the emergence from self-inflicted immaturity. The German Enlightenment philosophers also reflect on the limitation of enlightened thinking. The Prussian King Frederick the Great saw himself as an enlightened ruler; so did Catherine the Great in Russia. Both hosted enlightened philosophers and scientists.

The Enlightenment (1688-1804) emerged in three European countries, in rough chronological order in Britain, then France and it ended in Germany. This episode (Part I) starts with a general characterisation of the Enlightenment and then focuses on the Enlightenment in Britain. The Enlightenment owes its momentum to the Scientific Revolution, which brought about a fundamental change in world views. The Enlightenment is an application of scientific principles to the intellectual and social world. In Britain it takes the form of Empiricism and Liberalism (John Locke, David Hume).

Literature:

(The following texts are a small selection).

Berlin, I.: Three Critics of the Enlightenment (ed. by Henry Hardy) Pimlico 2000

Cassirer, E.: The Philosophy of the Enlightenment (1932/2009)

Gay, P.: The Enlightenment (Volume 1: 1995; Volume 2: 1970

Hazard, P.: The Crisis of the European Mind (1680-1715)

Im Hof, U.: Enlightenment. Making of Europe (1994/1997)

Porter, R.: The Enlightenment (Studies in European History) (1990/2001)

Porter, R.: Enlightenment: Britain and the Creation of the Modern World. Penguin Press 2000

Randall, J. H. The Career of Philosophy. Vol. 2 (1962/2022)

Torre, J. R.: The Enlightenment in America, 1720-1825 (Pickering & Chatto 2011)

The Stanford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy contain further material.

In this Episode I address the question of whether populism poses a danger to a democratic, open society. I define populism as charismatic leadership with a particular vision. I make a distinction between a democratic regime - with emphasis on the rule of law, the independence of institutions and freedom - and an open society - with the emphasis on accountability, contestability and critical scrutiny of political affairs, established traditions and figures in authority. I argue that it is important to uphold a ope and democratic society because of the fallibility of all political visions.

Literature:

The classic sources on the open society are:

Bergson, H.:  The Two Sources of Morality and Religion (1935; Osmania University Library, Internet Source) Popper, K. R.: The Open Society and Its Enemies. Volume I: Plato. (London: Routledge 1945, 1966) Volume II: Hegel & Marx. (London: Routledge 1945, 1962)

Good books on populism are:

Mounk, Y.: The People vs. Democracy: Why our Freedom is in Danger & How to Save it. (Harvard University Press 2018)

Müller, J.W.: What is Populism? (Penguin Books 2017)

Weyland, K.: Democracy’s Resilience to Populism’s Threat. Cambridge: Cambridge University Press 2024

I have published a review article on this whole question:Weinert, F.: ‘The Open Society Revisited’, in: Social Sciences  2025, 14 (3), 118; ⁠https://doi.org/10.3390/socsci14030118

On the notion of trust, you may consult my paper:

Weinert, F.: ‘The Role of Trust in Political Systems. A Philosophical Perspective.’ Open Political Science 1 (2018): 7-15

In the last episode on Human Rights, I left open the question of whether Civil Disobedience should count as a fundamental human right. A good example of this debate occurs in the film The Great Debaters (2007). After having defined civil disobedience (following the philosophers John Rawls and Jürgen Habermas), I argue that it should count as a fundamental human right - under specified conditions: it should be a non-violent, public and political act, undertaken by a group in society whose fundamental human rights are under threat. I discuss the role of civil disobedience in both democratic systems, in which it can play an active part, and in totalitarian regimes, in which it mainly plays a passive part. Civil disobedience can be seen as the right for fight for one's rights.

Literature:

- M. Walzer, Obligations: Essays on Disobedience, War and Citizenship (1970)

- J. Rawls, A Theory of Justice (1971: Ch. VI)

- J. Habermas, 'Civil Disobedience', in: Berkeley Journal of Sociology 30 (1985): 95-116 (translated form the German original in: Die Neue Unübersichtlichkeit, 1985: 79-99)

Following on from the last two episodes, which broadly dealt with issues of human freedom and justice, the question of the need for human rights arises naturally. I distinguish civil from human rights. Civil rights exist on the national level and they may differ from country to country. I propose three criteria to differentiate them from human or universal rights, which, as the term suggests, are transnational and transcultural. I explain why I think we need human rights, which I characterise as ethical benchmarks. They constitute standards for a dignified human existence.

Literature:

To start, there are excellent articles on human rights in the Stanford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy.