Philosophy Summaries - Modern Era

The period from the late 17th Century to the early 19th Century is often called The Enlightenment or The Age of Reason. Thinking emphasised reason, empirical evidence and the scientific method, and promoted individual liberty, religious tolerance, the separation of church and state, constitutional government and the application of rational principles to social and political reform.

Partly as a result of industrialization, political revolution and scientific advancements, philosophy in the 19th-century underwent a shift from Kantian idealism toward materialism, positivism, and existentialism.

In the 20th-century philosophy became very much the domain of professionals. There was a split between Analytic Philosophy (dominant in English-speaking countries and focused on logic, language and science) and European Continental Philosophy (focused more on existentialism, phenomenology and history).

Voltaire, 1694-1778 [9]

Voltaire pointed to that fact that history is being constantly revised to make the case that, apart from a few things in mathematics and logic, nothing can be known with certainty. There are no innate ideas; ideas that might seem to be innate, like those of religion, tend to be different in different cultures.

He saw doubt as less comfortable than certainty and this as the reason why people so readily accept church and government dogma. Science and education were more reliable ways of approaching truth. To avoid blinkering from the truth, speech should be free and government rules limited.

Unsurprisingly, these views got him into trouble with the authorities and landed him in prison more than once. Eventually, he was exiled from France, his country of birth. He spent time in London where he was influenced by English philosophy and science.

David Hume, 1711-1776 [7]

Hume was a British empiricist, born in Edinburgh. He posited that there are two types of statements, demonstrative statements based on reason which cannot conceivably be false, e.g. "5+2=7", and probable statements, based on experience which, even if they seem very likely, could conceivably turn out to be false without logical contradiction. An example might be "Elvis is dead".

The statement that the sun will rise tomorrow is neither of these as it could conceivably not happen without logical contradiction, but it is not based on experience either because no one has experienced it. It results from inductive reasoning. Such inductive inferences are therefore not provable. However, they are useful and are fundamental to the building of scientific knowledge. Inductive inferences are based on custom (something we are used to happening), but we can never be certain that they are true.

Jean-Jacques Rousseau, 1712-1778 [6]

Unlike many of his contemporaries, Rousseau claimed that man was fundamentally good and that in his natural state before the rise of modern civilised societies, he was virtuous and happy. He said that once man developed the concept of private property, those with property had to enact laws to protect their property from those without.

Thus he saw society as oppressing the masses with unjust laws that protect the aristocracy. His statement "Man was born free yet everywhere is in chains" was later adopted as a slogan in the French Revolution.

He saw the transition from man's natural state to the present civilised state as an inevitable consequence of man's ability to reason. But, in his work, The Social Contract, he suggested the repacement of existing societal structure with one where laws were made by the people, not just the elite.

Most of Rousseau's writings were banned in France and a warrant was issued for his arrest. He lived for a while in England, but later returned to France under a false name.

Adam Smith, 1723-1790 [8]

Adam Smith, born in Scotland, was possibly the most important economist of all time.

He realised that the motivation for human action can come from self-interst or benevolence towards others, but concluded from experience that self-interest was the dominant factor. Accordingly, his economic theory assumed economic motivation to be self-interest.

Smith saw all economic transactions as deals between two parties which benefit both parties. "Man is an animal that makes bargains." He argues that the ability to make bargains means that no one has to produce everything they need. Instead, people can produce just one thing and trade it for the other things they need. He referred to this as "division of labour". The invention of money made this trading much simpler by not requiring people to trade their goods with a different other person for every different thing that they need.

The factory system of the industrial revolution streamlined things further by allowing 20 people to produce far more of a particular item than the 20 could produce if working individually.

He saw the free market as being self-regulating according to the law of supply and demand, and predicted that the underlying self-interest of man could lead to a perfectly equitable society. However, he did recognise that it had its disadvantages, like unfair wage structure, monotonous work on productions lines etc.

Immanuel Kant, 1724-1804 [6]

Kant goes beyond Descartes' conclusion that he exists as a thinking entity. Using his experience of time, he argues that an outside world also must exist.

He also writes that the reasons why science had advanced so much in the previous two centuries were firstly that science ideas can be analysed mathematically and secondly that scientists routinely tested hypotheses by experiment. Unlike pure empiricists he argues that knowledge comes from the interaction of experience and a priori ideas. He sees space, time and substance as a priori ideas which we must have before we can understand anything through experience.

Kant refers to his view as transcendental idealism. He considers that concepts like space, time and substance are features of the world we experience rather than features of the world itself considered separately from experience, i.e. things-in-themselves. We cannot know anything about the things-in-themselves. However, it is a common error to think that we can.

Jeremy Bentham, 1748-1832 (Utilitarianism) [10]

Bentham was an English jurist, social reformer and philosopher regarded as the founder of modern utilitarianism.

He believed that all human activity is aimed at producing pleasure and avoiding pain. In The Principles of Morals and Legislation, he argues that all social and political decisions should be made with the aim of producing the greatest total happiness (i.e. the greatest happiness for the greatest number of people).

Such a system is simple and can be analysed mathematically using a felicific calculus.

Utilitarianism is one of my (David Ilsley's) favourite philosophical stances and the idea is elaborated upon in the article The Purpose of Life on the site M1Religion.com.

Georg Hegel, 1770-1831 [2]

Hegel considered all phenomena from consciousness to political institutions to be aspects of a single Spirit, which manifests itself as both mind and idea.

Over time, Spirit recognises mind and idea as aspects of itself and reintegrates them. This process of reintegration he calls 'the dialectic' and we (who are all aspects of the Spirit) understand it as history.

Hegel is thus a monist, believing that everything is an aspect of one thing, and he is also an idealist considering reality to be something that is not ultimately material.

John Stuart Mill, 1806-1873 [9]

JS Mill was a liberal British philosopher. An admirer of the simplicity of Jeremy Bentham's utilitarianism, he developed the idea further. Unlike Benthan, he felt that pleasures have different qualities, intellectual and moral pleasures being of greater value than more base physical pleasures.

His Harm Princliple states that government should not place restrictions on people's attempts to gain pleasure and avoid pain unless doing so adversely affetcs other people. He thus supported freedom of speech and individuality against the 'tyranny of the majority'.

Mill was an empiricist, believing knowledge is derived solely from experience and logic. He saw inductive reasoning as essential in developing knowledge, though he recognised its limitations.

In The Subjection of Women (1869), he argued for equality of women in marriage and society.

Soren Kierkegaard, 1813-1855 [2]

Soren Kierkegaard, born in Copenhagen, believed that objective, detached truths (like science) cannot explain the meaning of life. Instead, truth is found in the individual’s passionate commitment to their own life and choices. As such, he criticized conformity, arguing that modern society destroys personal authenticity and responsibility.

However, he saw personal freedom and the recognition that we are responsible for our own choices as producing a dizzying anxiety, in the same way that the impulse to jump off when standing on the top of a cliff produces anxiety.

Kierkegaard saw life as passing through three stages. The first is an Aesthetic Stage focused on pleasure, a stage than often leads to despair and a need for change. The second is an Ethical Stage focussed on responsibility and living within societal norms. The third is a Religious Stage involving a "leap of faith" into a personal relationship with God. He saw this faith as superior to reason.

Being a pious Christian, to him, the leap of faith was into Christianity.

Karl Marx, 1818-1883 [4]

Karl Marx and Friedrich Engels wrote The Communist Manifesto. In it, they argued that societies advance through a process of class struggle driven by economic conditions and technological innovation. Through history these have been the struggle between masters and slaves, between medieval lords and serfs, and between the owners of the means of production (bourgeoisie) and the workers (proletariat).

They argued that capitalism, characterised by exploiting workers' labour for profit, is inherently unstable, producing "alienation" and leading to its own downfall through a working-class revolution. This revolution results in a classless, communist society in which the means of production is owned by the workers.

The Russian revolutionaries were the first to build a society based on Marxist principles, though no society now adheres closely to them.

Friedrich Nietzsche, 1844-1900 [5]

Nietzsche observed that secularism and science had largely replaced religious morality. This is expressed in his famous quote "God is dead". He feared that this could lead to nihilism (a depressing belief that life is meaningless) and aimed to provide a positive alternative.

He saw Christian morality as a slave morality, and promoted instead a master morality that affirms strength and creativity. The main drive in life is a desire to master one's self, to reach one's full potential, to develop one's individuality and to embraces life fully. One should re-evaluate all inherited moral standards and discard those that inhibit life and growth.

He also argued that there is no objective truth, suggesting instead that all knowledge is interpreted through a person's perspective, biases and desires.

Nietzsche contracted diphtheria and dysentery at age 26 and suffered ill health from then on. At age 45 he collapsed in the street while trying to stop a horse from being whipped and suffered a mental breakdown from which he never recovered.

John Dewey, 1859-1952 [8]

John Dewey belongs to the philosophical school known as Pragmatism which arose in the US in the late 19th Century. Strongly influenced by the work of Charles Darwin, he saw humans as part of the natural world, having to deal with the problems that arise from unpredictable changes in that world.

He saw philosophy not so much as a means of finding the ultimate true nature of things, but more as a means of gaining a perspective which will help us to deal with the changing world.

He pointed out that two approaches to this have been widely adopted. The first is appealing to higher beings (gods) for help; the second is seeking to understand the world so that we can gain some control over it.

Bertrand Russell, 1872-1970 [8]

Bertrand Russell pioneered analytic philosophy, focusing on logic and science to resolve metaphysical issues. He promoted the breaking down of complex philosophical issues into their simplest components using formal logic, thus attempting to make philosophy as precise as science. He saw mathematics as completely derivable from logical axioms.

His work on language aimed to analyze the connections between words and reality, showing that grammatical form does not always reflect logical structure.

Russell was an empiricist, seeing knowledge by acquaintance (direct sensory experience) as superior to inferred knowledge. However, he proposed indirect realism, arguing we perceive "sense data" (mental images) rather than the external object directly.

He was an atheist and a monist, viewing mind and matter as different arrangements of a single, "neutral" underlying substance.

His ethics were broadly utilitarian. He advocated for social justice and a fair distribution of work such that everyone gets a good work-life balance with time and resources for play. He promoted education, free thought, pacifism, and nuclear disarmament, issues which earned him two stints in jail, the second at age 89.

Ludwig Wittgenstein, 1889-1951 [3]

Wittgenstein was an Austrian-British philosopher whose work focussed largely on the analysis of language and its limitations.

In his Tractatus Logico-Philosophicus, he proposed that language is a logical picture of reality, that a proposition is meaningful only if it can be pictured in the world or verified, and that language has limits, metaphysics, ethics, and aesthetics being "unsayable" because they cannot be pictured. His goal was to solve philosophical problems by outlining the boundary between sense and nonsense.

His later work, Philosophical Investigations, published post-mortem, retracted some of his earlier ideas. In this, he said that

> meanings are not direct pictures, but rather are determined by the context in which words are used,

> language consists of various, rule-governed activities (e.g., giving instructions, describing, joking),

> concepts often lack a single defining feature and are instead connected by overlapping similarities, and

> language is inherently public and social, not a private mental process.

Wittgenstein's varied and somewhat tragic personal life makes for an interesting read.

Martin Heidegger, 1889-1976 [4]

Heidegger was interested in ontology, which looks at the question of being. Unlike earlier philosophers, he defined being human not in terms of physical characteristics, but in terms of what it is like to be human.

He saw humans as being intimately involved in a practical world and defined by their contexts, relationships, and concerns. He saw time as an integral feature of this being, and authentic existence as being achieved by being aware of the span of our lives, accepting our mortality and making decisions on what we will devote our time to accordingly.

In his later work, he argued that Western metaphysics had lost touch with the question of Being, and that deep philosophical questions about the world needed a more poetic approach than just the tranfer of information.

Karl Popper, 1902-1994 [10]

Popper aimed to clarify the scientific method. He said that science works by observation followed by induction. For example after sighting numerous white swans and none of any other colour, one might induce that all swans are white. Such a conclusion cannot be proven. But it can be disproved - by finding a black swan.

Nothing is proved in science. Theories are developed by the process of induction and are accepted until they are disproved. Newton's theory of universal gravitation was accepted until disproved by observations that showed Einstein's theory of relativity to be correct rather than Newtons theory of gravitation.

Being falsifiable (able to be disproved) is an essential quality of any scientific theory. An unfalsifiable statement like "All human experience is a virtual reality fed to the brain by a computer" do not form part of the body of scientific knowledge. Not being part of the body of scientific knowledge of course doesn't mean that the statement is wrong. It is just that it is not the kind of statement which is subject to scientific investigation.

Jean-Paul Sartre, 1905-1980 [10]

Sartre makes the point that, if we make something, we make it for a purpose, and this purpose (or essence) determines its design. The essence of a made object comes before its existence.

It is commonly believed that humans were made by God for a purpose. But Sartre asserts that there is no God. Thus we are not made for any purpose. Our existence precedes our purpose and in fact we have to create our own purpose. We are free to create whatever purpose we want to create.

This freedom is unique to humans. Of course there are physical limitations to what we can become, but many people are also limited by habit. It is important to be aware of what we are trying to achieve with our lives.

We also have a responsibility for our choices in that they can affect others, through direct action on our part and through example.

Albert Camus, 1913-1960 [9]

The French philosopher Camus says that, though most people strive to find meaning in life, the meaning they might find is only in their consciousness; it is not an aspect of the universe as a whole. Thus he sees life as meaningless and absurd.

However, he does not regard this as a depressing idea. Instead, he says that once we accept life's meaninglessness, then we are in a position to live life fully.

This idea is examined further in my article The Purpose of Life.