Ludwig Wittgenstein’s wooden cabin in Skjolden, Norway (Alamy Stock Photo)

One hundred years ago, a slim volume of philosophy was published by the then unknown Austrian philosopher Ludwig Wittgenstein. The book was as curious as its title, Tractatus Logico-Philosophicus. Running to only 75 pages, it was in the form of a series of propositions, the gnomic quality of the first as baffling to the newcomer today as it was then.

1. The world is all that is the case.
1.1 The world is a totality of facts not of things.
1.11 The world is determined by the facts, and by their being all the facts.
1.12 For the totality of facts determines what is the case, and also whatever is not the case.
1.13 The facts in logical space are the world.

And so on, through six propositions, 526 numbered statements, equally emphatic and enigmatic, until the seventh and final proposition, which stands alone at the end of the text: “Whereof we cannot speak, thereof we must remain silent.”

The book’s influence was to be dramatic and far-reaching. Wittgenstein believed he had found a “solution” to how language and the world relate, that they shared a logical form. This also set a limit as to what questions could be meaningfully asked. Any question which could not be verified was, in philosophical terms, nonsense.

Written in the First World War trenches, Tractatus is, in many ways, a work of mysticism. A believer, Wittgenstein regarded part of the task of philosophy as sorting what was sayable from what was unsayable, a demarcation which left God, religion and ethics outside the realm of philosophical thinking. “Perhaps,” he wrote in a letter home from the front, “the nearness of death will bring light into life. God enlighten me.” Tractatus is the fruit of this engagement.

Nietzsche wrote that “During times of peace the warlike man makes war upon himself” but for many thinkers there has been no need to turn inwards. The 20th century, with its two world wars, produced a wealth of philosophers who wrote their work in extremis – French philosopher Jean Cavailles produced his great work, On Logic and the Theory of Science, as a prisoner of war; Louis Althusser first engaged with Marx during five years interred in Schleswig-Holstein, while Simone Weil fought as part of the Durutti Column in the Spanish Civil War, which coincided with her despair at politics and her shift towards religious thinking.

Wittgenstein was 25 years old at the start of the First World War. The son of one of Vienna’s richest industrialist families, he studied aeronautical engineering before turning to theoretical mathematics after reading Bertrand Russell’s The Principles of Mathematics and Gottlob Frege’s The Foundations of Arithmetic. The questions they raised about logic and mathematics left him, he later said, in “a constant, indescribable, almost pathological state of agitation”.

Unable to study under Frege, in 1911 he arrived unannounced at Russell’s study in Cambridge, soon dominating his lectures on propositional logic. It was the start of an exhausting, difficult relationship between the two – Russell loved him as “the young man one hopes for”, yet described him as an “infliction”. Wittgenstein credited Russell with saving his life after nine years of loneliness, but his criticism of Russell’s work was such that the older philosopher was forced to recognise he could “not hope ever again to do fundamental work in philosophy”.

The ambivalence in their relationship was not unique. Wittgenstein was notoriously solipsistic in his “friendships” and particularly harsh on those he regarded as intellectually inferior, which soon included Russell and later most other philosophers, with the exception of Frank Ramsey, who first translated Tractatus.

But it also often included himself. Tormented by problems of logic, he would feel total disgust with himself when unable to solve them. This self-loathing had a spiritual component: as he put it to Russell, he agonised about two things, logic and his sins, cursed as he was by “half talent”. Making war on himself had left him suicidal. What he needed was a war outside himself.

Philosophy in a time of war

In August 1914 it arrived. Wittgenstein enlisted and was assigned to an artillery regiment in Krakow on the Eastern Front, part of what his biographer Ray Monk terms “one of the most absurdly incompetent campaigns of the early months of the war”. Both sides were stationed in the wrong place, which for Wittgenstein meant several months on a ship in the Vistula river awaiting something, anything, to happen. Not only was he isolated; those he was closest to, including his lover David Pinset, were now on the enemy side. As ever, his thoughts turned to suicide.

And, as ever, he was stopped. This time, it was by a book. Browsing in a bookshop in Galicia, he chanced upon a copy of Tolstoy’s Gospel in Brief – the Russian writer’s retelling of the life of Christ by merging the four Gospels. The book would have a profound influence on Wittgenstein. With it virtually memorised, he would “recite Tolstoy’s words over and over again in my head” while under fire. It produced in Wittgenstein, Monk writes, “exactly the kind of personal transformation, the religious conversion, he had gone to war to find”. The book, Wittgenstein later wrote, “kept me alive”.

It also informed, dramatically, Tractatus. What was a work on logical symbolism became something much deeper, much wider, much stranger. Nothing in the existence of the mystical contradicted his theories of the logical. In occupying different realms, they shared none of the criteria of validity. They were, he argued, separate. His job was to show in any situation which was which, and ensure that the separation was absolutely enforced.

Tractatus introduces what has become known as the “picture theory of language”. For Wittgenstein there was a basic coherence between the structure of language and the structure of the world. This correspondence – between, for instance, the sentence “the cat sat on the mat” and the state of affairs that inspires it (a cat sitting on a mat) – is what enables language to represent reality. He uses the example of a gramophone record and a musical score. While each has a different materiality, they share a logical form: given the record one could deduce the score, and given the score, one could deduce the recording. Thus the relationship between language and reality.

Tractatus opens with “The world is all that is the case” and “The world is a totality of facts, not of things.” That is, the “world” is a totality of that of which we can speak, make propositions about, define. And it is “all the facts” – nothing is “world” which cannot be captured factually, which cannot be described.

One instance of a “thing” that cannot be described is how language does, in fact, represent the world. Here Wittgenstein points to a camera: the camera can picture the world, but it cannot picture the mechanisms which allow it to do so. It cannot represent its own method of representation. “Propositions can represent the whole of reality, but they cannot represent what they must have in common with reality in order to be able to represent it: logical form.” Philosophy has no place here. One cannot have a logic of logic; a meta-language is a language.

In fact, Wittgenstein writes, philosophy “should limit the thinkable and thereby the unthinkable. It should limit the unthinkable from within through the thinkable. It will mean the unspeakable by clearly displaying the speakable. Everything that can be thought at all can be thought clearly; indeed everything that can be said can be said clearly.”

What cannot be captured in propositions – what cannot be said clearly – is therefore either senseless, in that it does not offer a picture of possible facts, or nonsense, where “nonsense” is that which cannot be described without the description being absurd.

Logical positivism and the Vienna Circle

It was this idea which influenced the logical positivists of the Vienna Circle, whose “mission” was, like Wittgenstein, to demarcate between what is sense and nonsense, particularly with philosophy. The great unanswerable questions – about God, freedom, substance, causality – are unanswerable because they are not genuine questions. Whereof one cannot speak, thereof one should ignore, or point out that to speak of it leads only to nonsense. A sentence such as “It is raining” is verifiable, whereas “God is good” is not, and is therefore meaningless – a pseudostatement. One may feel it is true, but one cannot do any more than that. For the logical positivists this was held to be the case for most metaphysical questions, as well as aesthetics and ethics. The job of philosophy is to seek out this nonsense and strip it away from questions of meaning.

Where Wittgenstein differs absolutely from the logical positivists is precisely at this idea of nonsense. While agreeing that the unanswerable questions are not genuine philosophical questions at all – he himself sometimes described his philosophy as “therapeutic” in that it stopped one philosophising – this did not mean they could be dismissed. Simply, the truly religious was outside of speech. It could only be “shown” – and, as he puts it in Tractatus, “what can be shown cannot be said.”

To call a religious belief or practice “false” is, to use a basic philosophical term, to commit a category error. Truth and falseness belong to the sorts of “facts” which make up the world, the meaningful propositions of language. Religious belief – the mystical – is not a fact of this sort, and therefore to submit it to the truth tests of propositional logic is incorrect.

Wittgenstein here distinguishes between an explanation and an expression. Propositions are explanations, and can be true or false. But an expression, such as a religious belief, cannot. Take the example of pain. I can display pain by moaning or by saying “Ouch”. Or I can use the sentence “I am in pain.” The latter shares a grammatical structure with such phrases as “It is raining”, but it is in fact an expression in exactly the same way that “Ouch” is an expression.

In fact, “I am in pain” is simply a substitute for “Ouch” – it is a replacement, not a description, and it would be absurd for someone to say to me it is false. “There are indeed things that cannot be put into words. They make themselves manifest. They are what is mystical,” he wrote. We are in a space, outside of logic, we are where “language goes on holiday”. Thus “To be able to think outside the limit of thought – to be able to comprehend the mystical – would require that we think what cannot be thought.”

Religious belief shares this form: it manifests itself. It cannot be spoken of; rather, it must be shown. To believe in the resurrection is to have a rule to follow, to act as one should when one believes in the resurrection. As Wittgenstein would later argue, to understand a rule is to know what would count as acting in accord with it. A religious belief that does not affect the behaviour of the believer is not a religious belief.

Nor is it meaningless. Wittgenstein’s June 1915 Notebook breaks off from speculations about logic. He writes: “I know that this world exists… something about it is problematic, which we call its meaning… this meaning does not lie in it but outside it… the meaning of life, i.e., the meaning of the world, we can call God.” It is one’s “duty to oneself” to act on this belief.

And as for religious belief, so for ethics. “A certain characteristic misuse of our language runs throughout all ethical and religious expressions,” he would say in the only lecture he ever gave outside of his official teaching duties, his 1929 “Lecture on Ethics”. An ethical position is not that which can be said; rather, again it is that which can be shown. As he puts it in Tractatus, “it is impossible for there to be propositions of ethics. Propositions can express nothing that is higher.” Or, as he wrote in his war diary, “I am either happy or unhappy, that is all.”

Wittgenstein’s religious turn

In late 1918, Bertrand Russell produced his Introduction to Mathematical Philosophy. In a footnote about tautologies, he wrote: “The importance of ‘tautology’ for a definition of mathematics was pointed out to me by my former pupil Ludwig Wittgenstein, who was working on the problem. I do not know whether he has solved it, or even whether he is alive or dead.” He had not heard from his “former pupil” since 1915.

Wittgenstein had been at the front for most of that time. There, he often placed himself in the most dangerous positions, directly in the line of fire from Allied troops, an action which saw him decorated a number of times. In November 1918 he was captured by Allied forces and spent nine months as a prisoner of war.

All the while he continued to read Tolstoy, keep his Notebooks and work on the Tractatus, which was finally published in 1921 while Wittgenstein was working as a primary school teacher in rural Austria.

He and Russell had resumed contact, and the latter provided the introduction to the German edition of the Tractatus so as to lend weight to the work of this still unknown philosopher. Unlike Wittgenstein, Russell had not fought in the war, spending the duration in prison as a conscientious objector, an act of its own categorical bravery. Nor, emphatically, did he believe in God. Of Wittgenstein’s religious turn he would write: “He has penetrated deep into mystical ways of thought and feeling, but I think (though he wouldn’t agree) that what he likes best in mysticism is its power to make him stop thinking.”

It was not until 1929 that Wittgenstein returned to Cambridge, the intervening years spent madly oscillating between “stopping thinking” and thinking too much. He had, after the sort of long battle which only occurs in academia, been presented with his doctorate on the basis of Tractatus.

In his “Lecture on Ethics”, Wittgenstein described experiences which have an absolute value rather than an instrumental one. The first is being “safe in the hands of God”; the second is “seeing the world as a miracle” such that one is impelled to say “how extraordinary that the world should exist”.

This is not, of course, an experience of the world which is exclusive to the believer. One can wonder at the world without believing in God, and one can feel, with Wittgenstein, that there are things which fall outside the bars of the prison of language. That we still ask ourselves unanswerable questions may be a category error in philosophy, and cause for exasperation in a narrow version of science. But we do, and will continue to do so. That we find meaning in literature and music, in ritual and myth, is equally perplexing if all of life is supposed to be rational. And yet we do.

In many ways, Tractatus supports a version of the world where mysticism, to use one of Wittgenstein’s own metaphors, can be cut away like the rotten bit of an apple. But after 100 years we should still pay heed to Wittgenstein’s own reading at the time: “My work consists of two parts; that presented here plus all I have not written. It is this second part that is important.”

This article is from the New Humanist winter 2021 edition. Subscribe today.