The work of Karl Popper constitutes an important source of inspiration for liberalism. First of all I would like to explain the core of liberal thinking. It is the pursuit of freedom and justice. Liberalism is based on individualism, a concept that is often misused. Some people say that individualism is the same as egoism, but I couldn’t disagree more. In fact, individualism is a positive power allowing people to determine their destiny as an individual. Individualism leads to self-respect, self-fulfilment, self-development and emancipation from traditional relations and groups. Individualism is the anti pole against increasing anonymity, bureaucracy and uniformity of modern society. It lifts people from the grey masses and gives them the opportunity to find their own way within our society. 

It is correct that individualism goes hand in hand with self-interest, but there is nothing wrong with that. Self-interest is the source of prosperity and development. However individualism is more than self-interest. It is a never-ending process towards increasing liberty and self-reliance. For the citizen it is also a process of adaptation to social behaviour. Individualism is not an obstacle, but a condition for true solidarity. In his book On Liberty John Stuart Mill wrote: “Over himself, over his own body and mind, the individual is sovereign”. Starting from this definition, individualism may not be tempered, but on the contrary, must be encouraged, especially in those communities where people are suppressed due to religious, social and cultural traditions. 

Only liberalism beliefs in individualism, in freedom and the autonomy of the individual. Therefore it stands against each form of collectivism, nationalism or traditionalism in which men are inferior to the community, the collective morality or the nation. It is clear that liberalism has nothing to do with socialism, conservatism or nationalism. Liberalism and individualism are without doubt the most successful thoughts in history. They are the driving forces of anti dogmatic thinking. One of the first to recognize the importance of individualism was Pico delle Mirandola, a philosopher from the Renaissance. In his book Oration on the Dignity of Man he formulated his idea of man being his own creator. Man can degenerate to bestiality, or raise to divine. Afterwards, thinkers such as John Locke, Adam Smith, Immanuel Kant and John Stuart Mill elaborated these ideas. The central idea of Kant was ‘Sapere Aude’, ‘Dare to use your own sense’. He made clear that every human being is not a tool, but a goal. He defended the categorical imperative ‘Act only according to that maxim by which you can at the same time will that it would become a universal law’. In other words, each human being has the duty to care for his fellow humans. 

During history, liberalism and individualism was under pressure. Think about the twentieth century. Think about nationalism making humans inferior to the national community. During the First World War millions of young people died meaningless. Think about communism treating man as an object, a tool that could be switched on or off, used or thrown away. In order to achieve their goal, the ideal equalized society, communist leaders such as Stalin, Mao and Pol Pot drove millions of people into death. Think about Fascism making humans inferior to the will of the Führer. Under this system, man was considered as a healthy or unhealthy part of the national community. People who would not fit into the system were destroyed as happened with disabled persons, gypsies and Jews. Think about fanatic religious communities in which people were submitted to holy texts. Even today, in our Western countries, hundreds of thousands of people, mostly women, are suppressed in the name of God or Allah. 

Liberals fought against nationalists, communists, fascists and religious fanatics. And the fight was successful. With the boost of the liberal aspiration for freedom and justice, universal human rights were accepted, abuses condemned, dictatorships eliminated. The idea that we are not born Belgian, French, Czech or American, but as citizen of the world with a number of untouchable rights and liberties. Since the sixties in the Western hemisphere, liberalism provided more freedom, allowing individuals to have their own life under control. The sixties were a crucial decade. Some intellectuals consider May ’68 as a failure, as a movement of leftist activists and rebellious youngsters who sympathized with collectivist spectres. Those who examined this period more careful see that it meant the final breakthrough of individualism and liberal values throughout all levels of society. Look at the civil rights movement, the movement against Apartheid, the feminist movement and afterwards on the gay rights movement. During these years, many taboos disappeared. Here lies the basis of secularization, tolerance, rights of men, the equality of sexes, antiracism and above all individual freedom. Breaking loose from the chains of imposed morality, the liberation of women from their corset of religious dogma. The impact of this movement is still visible. It’s not a coincidence that in countries with liberal rulers, new laws are implemented on abortion and gay-marriage. 

During the past decades liberalism was also successful on the economic field. Until the eighties socialist parties and politicians protected collectivism, nationalizations and a greater impact of the state on the economy. This Keneysian thinking led to a fat state, an ineffective bureaucracy, a lack of creativity, unemployment and huge debts. Today most socialist parties transformed into social-democratic parties and accept free trade as the best system to create welfare. Under impulse of liberalism Western governments stopped subsidizing loss-making branches of the industry. They slimmed down their bureaucracies. They privatized branches such as telecom and aviation. They made the state more efficient. 

Some prefer to go beyond this. They not only want to remove the fat from state, but they also wish to dismantle the state, even in its most essential tasks. They call themselves neoliberals or libertarians. This leads to market fundamentalism. In contrast to Karl Poppers warning that we may not accept dogma’s, they have a blind believe in absolute freedom, absolute property rights, and in the absolute free market. Since the fall of the Berlin Wall and the thesis of the The End of History of Francis Fukuyama, neoliberals and libertarians consider free market as a kind of scientific certainty. Liberals never followed this dogmatic concept because they understand that not only freedom is necessary for a better society, but also justice. Liberals never adored the absolute freedom because they know that absolute freedom frequently causes negative effects for fellow humans and the whole society. Liberals refuse to submit themselves to blind capitalism because money and extreme selfishness are frequently bad advisors and can hurt society and freedom, and hamper opportunities for fellow humans. Liberals support the idea of the open society as defended by Karl Popper. 

As a student, Popper was a convinced Marxist but this belief changed very rapidly. At the end of the 1930’s, he fled the Nazi (trèt)threat, turned against every form of totalitarism and rejected the communist ideology. With his book The Open Society and Its Enemies he became an strong advocate for a liberal and democratic ‘open society’. A society of free civilians who are able to assess the policy, change it and dismiss their governors without shedding blood. He turned against prophets such as Plato, Hegel and Marx who defend a static society which results in oppression of possible changes. According to Popper, progress in society and the growth of knowledge are based on free discussion and a step by step reformation of society. It is a clear liberal point of view. In an interview with Giancarlo Bosetti, published in the book The Lesson of This Century, he stated: ‘I am a liberal’.

Although the totalitarian state is not good, unlimited freedom for every individual isn’t either, according to Popper. He reasons as follows: freedom means being free to do whatever you want. Who is free to do whatever he wants, is free to take the freedom of other individuals. Thus, unlimited freedom results into slavery. In his book All Life is Problem Solving he stated: “To protect freedom, freedom should be restrained”. Popper turned against every form of dogmatism and thus against absolute statements such as ‘truth’ and ‘certainty’. To him, all thesis are nothing but h(ai)ypotheses. A thesis stands firm as long as it is not countered by its counterevidence. The thesis that all swans are white stands firm until a black one arises. Here lies the basis for his falsification theory which is applicable to political philosophy as well. That’s why Popper is suspicious towards people who claim they’re convinced of anything “beyond all doubts”. In this way Francis Fukuyama was completely wrong in his book The End of History when he considered liberalism to be the sole and final victor on the ideological front. In an interview with Der Spiegel in 1992, Popper classified Fukuyama’s statements as follows: “These are but senseless statements”. 

Popper rejected every political and philosophical thought that started from its own infallibility. Think about communist party leaders such as Lenin, Stalin, Mao and Pol Pot. Think about fascist leaders such as Mussolini and Hitler. Think about theocratic leaders such as ayatollah Khomeini in Iran and the pope in the Vatican. Infallibility most commonly consist within closed societies where criticism isn’t allowed, where people live without freedom of speech, without freedom of belief or disbelief, and without freedom of association. Fundamentalism and infallibility walk hand in hand without paying attention to the atrocities this brings to numerous people. Popper warned that ‘those who promise us paradise on earth never produced anything but a hell.’ Criticism is to Popper the most important way to replace established beliefs with new ones. It is not the guarantee to establishing the perfect society but it is the key to detecting and abolishing social atrocities. 

The aversion to infallibility would have brought Popper up to arms today against market fundamentalism. Neo liberals and libertarians ‘believe’ that a free market and absolute freedom will always lead to a better result for mankind. Reality proved them wrong. In the book The Lesson of This Century Popper claims: “A free market without intervention does not and cannot exist”. Unconditional belief in freedom and a free market often lead to indifference towards people who can’t perform in society due to sickness or old age. It even leads to corrosion of the free market due to monopolies. A strong government is required to guard the free market from monopolies and price agreements. A strong government is required to defend the constitutional state and to guarantee the safety and freedom of its civilians. A strong government is required to help the sick, seniors and disabled, and to give children the educational opportunities to develop their own talents. 

In his lecture The History of Our Time: An Optimist’s View, Popper held at the University of Bristol, he gave a list of essential atrocities which had to be solved primary. He gave in this specific order: poverty, unemployment and other forms of social insecurity, sickness and pain, cruelty in penal law, slavery, religious discrimination and racism, lack of educational opportunities, rigorous class separation and war. Popper said: “We must construct social institutions, enforced by the power of the state, for the protection of the economically weak from the economically strong”. He clearly indicated that the basis of a democratic constitutional state contains both freedom and justice. A thesis, more developed by liberal thinkers such as John Rawls, Amarty Sen and Martha Nussbaum. Popper was very critical towards any government who claimed to hold the one and only truth. That was one of the reasons he fled the Nazi’s. Nevertheless, he didn’t turn against the necessity of an efficient government. 

His book, The Poverty of Historicism is an important contribution to liberalism as well. With full force, he turns against the theory that history develops towards a final situation, like Marxists think. According to Popper, historicism leads to a revolt against reason and in this way he turned against revolutions as well. He said: “If we don’t want to bring misfortune to the world once again, we have to give up on our dreams about making the world happy. Nevertheless we have to remain world improvers but in a modest way. We have to be satisfied with the never-ending task to decrease suffering, fight evil, clean up abuses”. Mankind can learn from its mistakes. By trial and error our knowledge grows, science advances. This insight is very important. The ‘critical rationalism’, Popper preaches, turns against every undemocratic and uncritical thinking as we have seen in the previous century under communism, fascism and narrow nationalism. Today, it would turn against religious fanatics and against market fundamentalists. 

Popper recognised that the future can not be predicted. “The future depends on what we do. We bear every responsibility. It’s our moral duty, not to predict evil but to fight for a better world”. This doesn’t mean he was pessimistic, on the contrary. ‘Optimism is a moral duty’, was his device. He meant that the future is open, and that we are responsible all together and we can do something about it together. In 1992 he stated: “We have a duty instead of predicting something bad, to support the things that may lead to a better future”. Anyone who strives for more freedom and justice in this world should read Poppers books. He never said his ideas were the one and only true. Therefore he was too critical and he hoped that after his death his ideas would be subjected to as most criticism as possible. This has happened by now and in many different occasions, yet his h(ai)ypothesis that the ‘open society’ is best for everyone, stands firm.

Today, the ‘open society’ is in danger once again. Religious fanatics act against liberalism and reject individualism. Look at radical Muslims who are menacing writers and politicians such as Salman Rushdie, Ayaan Hirsi Ali, Irshad Manji and many others. Salafists in particular pose a great danger to our freedom and democracy. In the West, they are using our constitutionally provided rights and freedoms to tear down that same freedom and democracy. Karl Popper thought tolerance was a great asset. But at the same time he warned against too much tolerance. “If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.” Look also at radical Jews and Christians who reject the separation of church and state. Read the book Kingdom Coming from Michelle Goldberg. She travelled through a country in the grip of a growing religious radicalism: the America of our time. From the classroom to the mega-church to the federal court, she saw how the growing influence of the doctrine that Christians have the right to rule nonbelievers – is threatening the foundations of democracy. Popper said: “We all remember how many religious wars were fought for a religion of love and gentleness; how many bodies were burned alive with the kind intention of saving souls from the eternal fire of hell”. Keep this in mind.

Nationalists, populists and extreme right-wing parties and groups also agitate against the individualism, openness and cosmopolitanism that form the core of liberalism. They also pose a great threat to the open society. They argue for protectionism, aversion to migration and a ‘people first’ policy. Think Trump, Bolsonaro, Putin and Orban. They seek illiberal states in which the judiciary is curtailed so that it can no longer function independently, and the muzzle of the critical, independent media. The storming of the Capitol in January 2021 gave us a glimpse of where all this could lead. Karl Popper would criticize it with all vigour, demonstrating that these are the true enemies of the open society.