"It is an hypothesis that the sun will rise tomorrow: and this means that we do not know whether it will . There is no compulsion making one thing happen because another has happened" is a well-known phrase from Wittgenstein Tractatus, but he himself does not abide by this rule when talking about how to use language.

What I mean by this is an example: Can a person who does not know German give instructions as to whether or not a sentence should be in a given German text?

Certainly not, he has to learn German first, but even if we assume that he has mastered all the previous texts written in this language, can it be said that according to a certain instruction, this sentence can be in one text Is it German or not?

Not yet, because "There is no compulsion making one thing happen because another has happened (in previous texts)",

However, Wittgenstein himself has the following instructions:

"If you see..."

{ a particular order in sentences and words, which leads to ambiguous concepts},

( know that words are misused),

"this should be avoided".

<-For example, the use of metaphors->

[Reference]: Lecture on Ethics, Cambridge


The subject matter is philosophy, neither language nor philosophy of language, the German metaphor of learning is used only because in a simple model we repeat certain patterns in previous and future texts, such as sunrise at Days before and after.

  • 2
    See the two previous sentences in the Tractatus: "6.363 The procedure of induction consists in accepting as true the simplest law that can be reconciled with our experiences. 6.3631 This procedure, however, has no logical justification but only a psychological one. It is clear that there are no grounds for believing that the simplest eventuality will in fact be realized." Feb 24, 2020 at 10:45
  • Your analogy is unclear, "will rise" is a prediction, "must be in a definite form" is a prescription. If we prescribe something we need not hypothesize what it must be.
    – Conifold
    Feb 24, 2020 at 10:46
  • W says that we cannot justify induction using only (deductive) logic. This does not mean that we cannot "use" it : most of human (and animal) life is based on expectations and assumptions about regularities. Feb 24, 2020 at 10:47
  • Having said that, what is exactly the connection with "language" ? We do not learn language "by induction". Feb 24, 2020 at 10:47
  • ,@Mauro ALLEGRANZA:It's not about us and our learning the language, it's about Wittgenstein and his rules and logic
    – dt128
    Feb 24, 2020 at 12:18

3 Answers 3


First, your example is not quite on point. For instance, I do not know German (except a word or two, here and there), but if you handed me a German phrase and asked me whether it came from Hegel's "Phänomenologie des Geistes", I could sit down and go through that text line-by-line — understanding not a word — and do a simple orthographic comparison. If I find those self-same letters in the same order the answer is 'yes'; if I reach the end of the book the answer is 'no'. This is essentially how a Google search works (well, Google searches are more sophisticated, but the idea is there), but the point is that there's no need to learn German or actually read the texts in question.

You'd have a more solid point if you asked if there exists a phrase that means the same as the phrase you've handed over; that demands a far higher level of comprehension.

But in any case, I think you've missed the point Wittgenstein is laying out. Wittgenstein is trying to draw out the distinction between knowledge and hypothesis, where the latter is a kind of belief based on perceived regularity. I know (perhaps) that the sun has risen many times in the past, because I have recoded a series of alternating nights and days that demonstrate the existence of past sunrises. I do not know that the sun will rise tomorrow in the same way; I can only hypothesize that it will do so, because it has always done so in the past. One can invoke all of the laws of physics and orbital mechanics that one likes, but those laws are themselves based entirely on perceived (past) regularity, and are projecting that past regularity into the future. Neither Wittgenstein nor I am suggesting that such hypothesizing is wrong or problematic, but it is by definition the invocation of a hypothetical, which can never be knowledge properly put. I mean (just for the worst case scenario) say we have something wrong in our understanding of the life-cycle of stars, and at midnight GMT tonight our sun suddenly happens to blow up into a red giant, swallowing the earth and its inhabitants. Sunrise is thus permanently cancelled...

The same could be said for your book example. Let's say I do know German, and I have read "Phänomenologie des Geistes" in the original, and I remember encountering the phrase you've handed me. Does that mean that I know that the phrase is in the text? Maybe there's a copy of the text that was revised by the author or an editor, removing the phrase; maybe over the years of publication and reprinting the phrase was accidentally lost or garbled. My belief that the phrase is in that text is a sound hypothesis based on my experience, but it is not necessarily true, and thus is not knowledge in the exacting sense of the term.

  • about example,Talking about a sentence from a book is not with the author, but how the sentence is used in the text, whether at the syntactic or semantic level.For example, Mr. W's law says that if you see a certain order in sentences and words, know that words are used badly, which leads to vague and ambiguous concepts, That should be avoided.
    – dt128
    Feb 24, 2020 at 17:11
  • 1
    @alwaystudent: I'm not sure I follow you. If I write these sentences — "this is a sentence", "A sentence is this", and "a this is sentence" — I know that the first too are properly formed and the last isn't, because I have an implicit understanding of the grammar of English. Is that what you're getting at? Feb 24, 2020 at 17:17

"To say that the sun will rise tomorrow is a hypothesis ... because it has no reason to happen because it has happened before" is a well-known phrase from Wittgenstein Tractatus, but he himself does not abide by this rule when talking about how to use language.

What I mean by this is an example: Can a person who does not know German give instructions as to whether or not a sentence should be in a given German text?


You are correct in noticing LW goes beyond logical induction as a learning model for language. It is uncontroversial that Wittgenstein and his contributions to the philosophy of language laid the groundwork for the science of language acquisition and showed that learning through formal logic and acquiring a primary language are fundamentally distinct ontologically.


While many here seem to be okay with your conflation of learning about periodic events and learning and using a language, it is without a doubt a category mistake which stems from a bad ontological presupposition that learning about physical, external reality and learning about language are the same. While they both are instances of learning and require experience, how the brain goes about learning about language systems and physical sensorimotor systems occur in physically DIFFERENT parts of the brain on a neurological level, and language use and temporal awareness and association aren't the same parts of the brain. This is an empirical fact, and concomitant with accepting science. Any philosopher living or dead, who claims otherwise, is engaging in metaphysical speculation that does not accord with empiricism and should be treated with suspicion. I would be curious to be challenged with any contemporary philosopher of language or psycholinguist who would accept such addled metaphysics. You are on the right track, however, because outside of Noam Chomsky, Wittgenstein, in my personal experience, is perhaps the most influential philosopher of language in the 20th century, although it came from his later work Philosophical Investigations. If LW doesn't seem to you to apply the same standards about learning through Hume's induction, and language acquisition, it's likely because he had even in the early days a sense that what went on under the hood wasn't the same.

You have to understand that before LW, linguists and logicians such as those of Frege's day and age were mired in a debate about the relationships among psychologism, logic, and language. Today, if you accept cognitive science, Frege's antipsychological position has been thoroughly defeated. At least, from an analytical philosophical position, the predominant Anglo-American tradition, which is very compatible with science particularly with Quine's defense and reworking of empiricism in both his Two Dogmas of Empiricism and his naturalized epistemology. But before Quine, was LW who is still very influential including influencing contemporary linguists such as Elanor Rosch and her work on language.


Sollte man einen Satz usieren, wenn man kein Deutsch kann? Vielleicht! (Excuse my very poor, converational German.)

Should one use a particular sentence if he doesn't know German? Maybe! Although, your question is broad, since "should" is a normative concept, and invites a host of value-laden concepts that will be contextually driven, but let's say neo-Nazi grammarians capture you and give you a choice to prove your devotion and they ask you to pick from two sentences, one of which means, "I will jump from the house" and the other "I love cats, dogs, und beer." In our Gedankspiel, your choices are:

A) Ich werde aus dem Haus springen.
B) Ich liebe Katzen, Hunden, und Bier.

One certainly has an imperative to survive, and if one were to evaluate language use not on the knowledge of German, but knowledge of English, one could be relative certain that Haus and house and Bier and beer are cognates and make use of that; hence, be able without any foreknowledge of Hochdeutsch glean some meaning because of similarity of orthography. (This is of course because English is actually a descendant of Plattdeutsch.) Of course, it becomes a nonsensical question to use a language and script outside of the PIE family.


The crux of your question is one of the extensibility and expressibility of language. Let's set aside your digression about a foreign language because it isn't needed. What you seem to want answered regarding LW's deviations from logical induction as a method of learning is the following:

Is the sentence "I entered the computer lab and rebooted Unit 32A, the one with the Intel Core i3-3220 3.3GHz Dual-Core that Parnesh built on 02/24/2020," an English sentence and if so, how would someone who even read every piece of "English" (whatever that may be) know for sure? This is an excellent philosophy of language question! Let's just run a quick argument to show a tenable contemporary answer.

Essentially, a natural language functions like a formal language insofar as it is generative. The violently paraphrased idea is this. One breaks down language into phonological, syntactical, semantical, and pragmatic cues to decide by parsing tokens much like a computer does when sending packets across a TCP/IP network. (See ISO's OSI for an intro into a classic digital communications ontology.) Thus, the mystery LW was trying to tackle has been solved by psycholinguists awhile ago. One can express the membership of a sentence to a language using logical modality (probably, possibly, almost certainly) based on one's language experience and a sense of cognitive dissonance (the ACC has been implicated in this process). In fact, it's LW's family resemblance that laid the ground for prototype theory which allows us to say that ANY sentence belongs to a "language" to a degree because a descriptivist account of a language is at best a measure of central tendency of idiolects. National languages as they currently exist (Spanish, English, Italian, French, usw.) are a relatively new phenomenon, in fact, that developed alongside of the nation-state in the 19th century. There is no distinct line between dialect and language, in fact. My grandfather spoke Veneto. Like Catalan, at what point is it a language? Intelligibility like membership is graded. And it is exactly this point that LW is largely responsible for inspiring through his passage in Philosophical Investigationsabout family resemblance. In paragraph 67 he says:

I can think of no better expression to characterize these similarities than "family resemblances"... And I shall say: [language] 'games' form a family.

  • َ@J D: I think Wittgenstein was quite right, when he said "don't use metaphor and allegory" in my question, the metaphor of "learning German" completely sidestepped the main question of Wittgenstein and his philosophy.
    – dt128
    Feb 25, 2020 at 18:29
  • @alwaystudent And anyone who doesn't answer to why you have perceived a difference in how Wittgenstein tackles subconscious language acquisition as part of the language game different from standard concious logical methods of knowledge expansion such as Hume's induction has side-stepped your question, and missed LW's contribution to the philosophy of language.
    – J D
    Feb 26, 2020 at 0:18

What Wittgenstein actually wrote in the Tractatus is the following:

6.36311 It is an hypothesis that the sun will rise tomorrow: and this means that we do not know whether it will rise.

6.37 There is no compulsion making one thing happen because another has happened. The only necessity that exists is logical necessity.

6.371 The whole modern conception of the world is founded on the illusion that the so-called laws of nature are the explanations of natural phenomena.

6.372 Thus people today stop at the laws of nature, treating them as something inviolable, just as God and Fate were treated in past ages. And in fact both are right and both wrong: though the view of the ancients is clearer in so far as they have a clear and acknowledged terminus, while the modern system tries to make it look as if everything were explained.

There isn't anything here about language. What he's concerned about here, is a position that was articulated by Hume, who most likely picked up from al-Ghazali. That is the question on what constitutes neccessity. Al-Ghazali drew a distinction between divine, logical and natural neccessity. Both Hume and Wittgenstein dropped divine neccesity, settling on focusing on the relationship between logical and natural neccessity.

Because of this focus, Wittgenstein has missed out some essential information on his 'hypothesis'. Which is that the sun has risen on the earth for the last four and a half billion years. Thus we can safely discard this as a mere hypothesis, so far as empirical science is concerned.

  • As I said,The subject matter is philosophy, the German metaphor of learning is used only because in a simple model we repeat certain patterns in previous and future texts, such as sunrise at Days before and after.(In every form of learning, we deal with estimation and predictions, whether learning science and the language of nature, or learning the language of man. )
    – dt128
    Feb 29, 2020 at 18:10
  • @alwaystudent: I quoted the relevant text and pointed out what it had to say - unlike your disinformation tactics. Mar 2, 2020 at 17:26

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