In short
In his Lecture on Ethics (given in Cambridge in 1929, published in 1965) Wittgenstein argues that ethical judgements of absolute value are not statements of fact, so every attempt to express them runs against the limits of language. He still deeply respects that attempt. It is his most accessible text.
A Lecture on Ethics is the only popular lecture Wittgenstein ever gave: a short talk in plain English, read to a student society in Cambridge in November 1929. In it he argues that ethics tries to say something that cannot be said, and that he nevertheless respects this attempt deeply. If you want to know what the silence at the end of the Tractatus is about, this is the clearest place to look.
What it is and how it came about
The lecture was given on 17 November 1929 to the Heretics, a Cambridge discussion society that C.K. Ogden had helped found and that invited speakers on religion, science and morals. He wrote the talk in English and, unusually for him, aimed it at a general audience. The drafts survive in his papers (MS 139a, MS 139b and TS 207, as listed by the Wittgenstein Archives in Bergen).
He never published it. It first appeared in 1965 in The Philosophical Review, together with Friedrich Waismann's notes of conversations with Wittgenstein on ethics and religion. A German translation, Vortrag über Ethik, followed, and in 2014 a critical edition with all the drafts was published by Edoardo Zamuner, Ermelinda Valentina Di Lascio and David Levy (Wiley-Blackwell).
What it says
Wittgenstein starts from G.E. Moore's definition (ethics is the general enquiry into what is good) and widens it to include the enquiry into what is valuable, what makes life worth living, the right way to live.
Then he draws his key distinction. Words like "good" and "right" have a relative sense and an absolute sense. A good chair is good for sitting on. A good tennis player plays well. Such judgements are really statements of fact in disguise. But suppose I behave badly and someone says: you ought to want to behave better. Nothing follows about what I happen to want. That is an absolute judgement of value, and it is the one ethics is after.
Now imagine, he says, a book that describes every fact in the world. It would contain no ethical proposition. Even a murder, described in full, would be one event among others, like a stone falling. Facts are on one level; absolute value would have to be on another.
So where does ethical language come from? Wittgenstein describes three experiences of his own: wonder at the existence of the world, the feeling of being absolutely safe whatever happens, and the feeling of guilt. When we try to put these into words, we produce nonsense. You can wonder that a tree is so tall, but not that the world exists, since you cannot imagine it not existing.
His conclusion is double. Ethics cannot be a science and adds nothing to our knowledge. Every attempt to express absolute value is, as he puts it, a matter of
running against the walls of our cage
A Lecture on Ethics (1929)
And yet he refuses to sneer. Ethics, he says, is
a document of a tendency in the human mind which I personally cannot help respecting deeply
A Lecture on Ethics (1929)
How to read it
This is the easiest text Wittgenstein wrote. It is short, written in ordinary English, full of examples, and needs no background. You can read it in half an hour on the Ludwig Wittgenstein Project, which offers it in many languages.
Read it next to the last pages of the Tractatus (6.4 to 7). The lecture makes their argument in a gentler voice, with the distinction between saying and showing now applied to everyday experience rather than logic.
Why it matters
The lecture is our best evidence that the Tractatus did not dismiss ethics as unimportant, but placed it beyond what language can state. It supports the view, taken up in different ways by traditional and resolute readers, that the ethical point of the early work was real. Some interpreters read the lecture as a straightforward account of inexpressible value; others hear in it the beginnings of the later idea that the problem lies in how we use words. Both readings have their defenders.
It also shows a side of Wittgenstein rarely visible in his technical work: personal, almost confessional, and serious about the experiences that drive people to religion. That side returns in the remarks collected in Culture and Value.
Verdict
Read this if you want a first taste of Wittgenstein, if you are curious about what he thought of ethics and religion, or if the end of the Tractatus left you puzzled. It is the most accessible door into his early thinking. Few philosophical texts say so much in so few pages.
Frequently asked questions
What does Wittgenstein mean by absolute value?
A value that does not depend on any goal or wish. 'A good chair' is relative: good for sitting. 'You ought to want to behave better' is absolute: it holds whatever you want. Wittgenstein argues that no statement of fact can express this.
Did Wittgenstein think ethics was meaningless?
He thought ethical sentences cannot state facts and are in that sense nonsense, but he did not dismiss ethics. He called it a tendency of the human mind he could not help respecting deeply.
When was the Lecture on Ethics published?
It was given on 17 November 1929 to the Heretics society in Cambridge and first published in The Philosophical Review in 1965. A critical edition appeared with Wiley-Blackwell in 2014.
Sources
wittgenstein.be, “A lecture on ethics”, https://wittgenstein.be/en/books/lecture-on-ethics/ (2026-10-20)