In this episode I briefly describe the events of the French Revolution and then turn my attention to the life and times of two prominent 'engaged philosophers': Voltaire and the Marquis de Condorcet. Both fought against the injustices of the Ancient Regime, i.e. the time prior to the French Revolution, when France was ruled by absolute monarchs. Through their active defence and rehabilitation of the victims of injustice both Voltaire and Condorcet brought to light the religious intolerance and the obscurantism of their age.

I also briefly discuss the controversial German philosopher G. W. F. Hegel who became the philosopher of the French revolution.

I conclude this episode with a brief look at engaged intellectual in our age: Bertrand Russell, Jean-Paul Sartre and Noam Chomsky.

Literature:

A good, concise introduction to the ideas of the French Revolution is George Rudé, The French Revolution (1988). A classic, comprehensive study is Albert Soboul, The French Revolution 1787-1799 (English translation 1975).

There are numerous biographies of Voltaire. For this episode I used Jean Orieux, Voltaire (2 volumes 1977). For Condorcet I used the brilliant biography of Elizabeth & Robert Badinter, Condorcet - Un Intellectuel en Politique (1988), which unfortunately has not been translated into English.

The next couple of episodes continue Part I on Political Philosophy.

The next two episodes will discuss the impact philosophical ideas have had on the social and political world. In the current episode (17), I start with the influence John Locke's political philosophy had on the adoption of the English Bill of Rights in the wake of the Glorious Revolution (1688), as well as French philosophers and the American Declaration of Independence (Jefferson). Locke, the Enlightenment philosopher, is often seen as the Godfather of liberalism. His ideas laid the foundations for liberal democracies worldwide.

In the following episode (18), I look at two French philosophers around the time of the French Revolution: Voltaire and Condorcet, and describe their fights for justice. Then I turn to Human Rights and the state of democracy in the face of the rise of populism.

Literature:

The classic source of liberalism is John Locke's The Two Treatises of Government, especially Part II, first published in 1690. His Letter Concerning Toleration (1689) is also worth reading. Every good book on political philosophy will discuss Locke's ideas and his influence. Voltaire's Lettres Philosophiques (1734), his Treatise on Religious Tolerance (1763) and his Dictionnaire Philosophique (1764) are well worth perusing.They give a flavour of Enlightenment ideas.

The question of whether humans enjoy free will (or not) has occupied people for centuries. Science has not yet found a definitive answer but we are all familiar with the phenomenon. When we want something (a mental event), we get up to get it (a physical event). When something happens to us (a physical event), we react with, say, sadness or joy (a mental event). How is this possible? How can physical events influence mental states? And how can mental states lead to physical events? In this Episode I introduce to rival accounts: determinism (which claims that we are not free agents) versus libertarianism (which holds that our mind are free to choose between options). I discuss the pros and cons of each position and conclude that I am more convinced by the libertarian argument, i.e. the belief in the freedom of the will, than determinism - unless proven otherwise.

Literature:

There is a vast amount of literature on free will, consciousness and the mind. I found the following helpful: Susan Blackmore, Consciousness-An Introduction (2003); Richard Swinburne (ed.), Free Will and Modern Science (2011).

There are also good articles in the Stanford Encyclopedia of Philosophy and the Internet Encyclopedia of Philosophy.

In previous Episodes, I have made many references to the laws of nature. Laws of nature are the regularities in the natural world, which exist independently of our knowledge of them. But in the textbooks of science you find many equations which encode the natural regularities. These equations are the laws of science. The laws of science are only approximately true because the employment of mathematics involves the use of abstractions and idealisations. The laws of science are subject to modifications, but the laws of nature just are. I limit myself to two philosophical attempts to explain what the natural laws tell us about the natural world: the regularity view and the structural view.

Literature:

The material of this episode draws on my Introduction to the volume Laws of Nature , edited and introduced by Friedel Weinert (1995).

In this Episode, I discuss some systematic ways in which discoveries are made in science. This follows on from Episode 13 (A, B) which introduced thought and real experiments. In this Episode I look at methods - systematic ways - to go about scientific discoveries. There are three methods: two different forms of induction and deduction. Induction works either by inferring from some to all cases (from 'some ravens are black' to 'all ravens are black') or by the method of elimination. To illustrate the latter method I compare the work of a scientist who tries to solve problems, to the work of a detective who tries to solve a crime. The detective tries to eliminate potential suspects to identify the real culprit. The scientist tries to eliminate possible solutions to find the real solution to a scientific problem. In between the two methods stands deductivism: according to this method a scientist makes a hypothesis - a bold conjecture - and then submits it to rigorous tests.

Literature:

I discuss these methods in more detail in Friedel Weinert, Copernicus, Darwin & Freud (2009) and Karl Popper-Professional Philosopher and Public Intellectual (2022).

Part B of this Episode concentrates on imaginary and real experiments in the modern era. I introduce Foucaults' famous pendulum experiment (1859), which gave a visual demonstration that the Earth turns on its own axis. I propose that thought experiments answer 'what-if' questions about the natural world. They are models of possible worlds. The episode finishes with a discussion of the famous double-slit experiment on the atomic level. It started out as a mere thought experiment before becoming an iconic a real experiment. It demonstrates the weird behaviour of quantum particles, i.e. the wave-particle duality.

Literature:

You can find brief, handy descriptions of scientific experiments in Rom Harré, Great Scientific Experiments (1981) and George Johnson, The Ten Most Beautiful Experiments (2009).

Episode 13 (A, B) is devoted to the topic of experiments in science: thought experiments and real experiments. They are as important as grand scientific theories. Part A focuses on thought and real experiments from antiquity to the 17th century. I explain the function of such experiments and discuss some famous examples. How do you 'prove' that the universe if infinite (Archytas of Tarentum, ca 430-345 BC), that the Earth rotates (Aristotle and Galileo) and how do you measure its circumference (Erastothenes, 240 BC), when you cannot make direct measurements? Listen to Part A to find out!

Literature:

You can find brief, handy descriptions of scientific experiments in Rom Harré, Great Scientific Experiments (1981) and George Johnson, The Ten Most Beautiful Experiments (2009).

This episode is devoted to the topic of time travel; time travel in a conventional sense, which relies on time machines to travel either into the future or the past. (I do not discuss forms of time travel, which may be permissible by the laws of physics.) It is advisable to separate these two different scenarios. Time travel into the future - as in H. G. Wells's novel The Time Machine - leads to odd situations, giving rise to the opportunity of 'harvesting' future knowledge for its use in the present. For instance, you could observe the results of a lottery draw tomorrow, return to today and tick the winning numbers.

However, time travel into the past leads to straightforward contradictions. It is agreed that the past is fixed and cannot be changed. But time travel into the past seems to imply that you can go back and change the past. Lots of possibilities seem to offer themselves. You could change world history, kill your younger self or simply change your appearance. Then the Second World War happened and did not happen! These contradictions seem to rule out time travel into the past. However, if you are willing to contemplate parallel universes, these logical inconsistencies can be avoided. You can travel from your own to another universe and do there, as I illustrate, what you are prevented from doing in your familiar universe.

Literature:

One of the most comprehensive books on time travel is P. J. Nahin, Time Machines (1993). The material for this episode is drawn from Friedel Weinert, The March of Time: Evolving Conceptions of Time in the Light of Scientific Discoveries (2013).

This episode continues the investigation into the nature of time. In particular it introduces two philosophical models of time, which are more in tune with scientific thinking. One is Newton's realist view of time. The other, in direct opposition to Newton, is the relational view of time. It was defended by Gottfried Wilhlem Leibniz (1646-1716) in the 17th century. Modern physics seems to be sympathetic to the relational view, at least according to some textbooks on the theory of relativity. I end this episode with a discussion of time in modern physics: the behaviour of atomic systems, and the behaviour of clocks in fast-moving reference frames (rockets) and gravitational fields (for example near or far away from the earth).

I explain that GPS would not work without taking the result of Einstein's Special and General theory of relativity into account. Einstein's theories have led to a revolution in our understanding of time, including the question of time travel.

Literature:

The material for episodes 10 and 11 is drawn from Friedel Weinert, The Scientist as Philosopher: Philosophical Consequences of Great Scientific Discoveries (2004) and The March of Time: Evolving Conceptions of Time in the Light of Scientific Discoveries (2013).

Episodes 10 and 11 are an inquiry into the nature of time. It is so large a topic that I have split it into two parts. The current episode, 10, discusses aspects of the measurement of time and the use of clocks. It is easier to discuss the measurement of time than to deal with the philosophical question of the nature of time. In the current episode, after having argued that clocks need to rely on precise and regular natural processes, I briefly mention some cultural and scientific conceptions of time.

Then I begin to look at philosophical models of time. In the current episode I introduce idealist views of time, which make the mind the instrument of time (Saint Augustine, Emmanuel Kant). I explain why they are unsatisfactory.

This episode ends with a look at units of time, that is natural, conventional and semi-conventional units of time. Whilst natural units make a reference to natural processes (summer must coincide with the highest position of the sun in the sky), conventional units of time (New Year, the lengths of the calendar months) make no reference to natural events. Episode 11 continues the investigation into the nature of time.

Literature:

You can find a very nice overview of time travel in science and literature in P.J. Nahin, Time Machines (1993). The material for episodes 10 and 11 is drawn from Friedel Weinert, The Scientist as Philosopher: Philosophical Consequences of Great Scientific Discoveries (2004) and The March of Time: Evolving Conceptions of Time in the Light of Scientific Discoveries (2013).