He's talking about understanding meaning. He's not talking about 'understanding choosing a word when speaking' - whatever that is supposed to mean. The only confusion is yours. Stick to what's in the text.

Don't be silly, there's no such distinction. Meaning is use. Using a word is speaking. Understanding the meaning of a word is understanding speaking. Either we choose our words when we speak, we do not, or sometimes we do and sometimes we don't.

At 139 he is asking what comes before our mind when we understand a word. It doesn't seem like the use of the word comes before our mind, because we understand in a flash, and so it is impossible that we'd be understanding the entire use of the word, which is extended in time. It's perhaps a picture, or something picture-like which comes before our mind.

And how can what is present to us in an instant, what comes
before our mind in an instant, fit a use"?
What really comes before our mind when we understand a word?—
Isn't it something like a picture? Can't it be a picture?

He concludes that even if understanding a word consists of something picture-like coming to your mind when you hear or imagine that word, it is still possible to use the word in other ways which are not consistent with that (the picture-like thing, or whatever it is), which comes to your mind in association with the word.

So at 140 he proceeds to question this idea that whatever it is (picture-like thing) which comes to your mind in association with the word, "forces" a particular use of that word on you. There doesn't appear to be other picture-like things in the mind which could account for these other [random-like] uses, so he suggests that there must be other processes involved [in choosing a word for use].

What was the effect of my argument? It called our attention to
(reminded us of) the fact that there are other processes, besides the one
we originally thought of, which we should sometimes be prepared to
call "applying the picture of a cube". So our 'belief that the picture
forced a particular application upon us' consisted in the fact that only
the one case and no other occurred to us. "There is another solution
as well" means: there is something else that I am also prepared to call
a "solution"; to which I am prepared to apply such-and-such a picture,
such-and-such an analogy, and so on.
What is essential is to see that the same thing can come before our
minds when we hear the word and the application still be different.
Has it the same meaning both times? I think we shall say not. — 140

Don't be silly, there's no such distinction. Meaning is use. Using a word is speaking. Understanding the meaning of a word is understanding speaking. Either we choose our words when we speak, we do not, or sometimes we do and sometimes we don't. — Metaphysician Undercover

The distinction is the one you have needlessly introduced. Wittgenstein is talking about understanding meaning. You are talking about understanding choosing (?).

There is not such distinction and that's what I said. So obviously I am not introducing the distinction, you are. Because you do not want to face the subject Wittgenstein is discussing, that of choosing words, you have introduced an unwarranted separation between understanding meaning and understanding the choosing of words for use, in an attempt to ignore the latter. Meaning is use, and we use words by speaking and writing, and this implies choosing which words will be used. Wittgenstein, is talking about choosing words here. How could you possibly read through 139 and 140 without noticing this? .

139...
Suppose I were choosing between the words "imposing", "dignified", "proud", "venerable"; isn't it as though I were choosing between drawings in a portfolio? ...because one often chooses between words as between similar but not identical pictures; because pictures are often used instead of words, or to illustrate words; and so on.
...
140. Then what sort of mistake did I make; was it what we should like to express by saying: I should have thought the picture forced a particular use on me? How could I think that? What did I think? Is there such a thing as a picture, or something like a picture, that forces a particular application on us; so that my mistake lay in confusing one picture with another?

Meaning is use, and we use words by speaking and writing, and this implies choosing which words will be used. Wittgenstein, is talking about choosing words here. How could you possibly read through 139 and 140 without noticing this? . — Metaphysician Undercover

You complained earlier that Wittgenstein was vague about this, but now you seem to find that he is very clear about it, so which is it?

Wittgenstein does indeed talk about choosing between words in his discussion of mental pictures and meaning, where he is discussing understanding the meaning of a word. What you have provided zero evidence for is that he is discussing understanding choosing. You might recall your original complaint:

...he doesn't properly differentiate between "understanding" in the sense of understanding a spoken word, and "understanding" in the sense required to choose a word in speaking. These two are distinct mental processes, and though he speaks of these activities, he seems to conflate them into one sense of "understanding". — Metaphysician Undercover

In your latest post, you demonstrate that Wittgenstein discusses choosing between pictures at §139. That may be, but he does not discuss understanding choosing, which is something that only you have attempted to interject into the discussion.

If I were to follow you down this rabbit hole of confusion: understanding the meaning of a word is (arguably) a requirement of choosing to use that word. Wittgenstein doesn't need to "properly differentiate" between your two senses of understanding because he is not at all talking about understanding choosing.

In your latest post, you demonstrate that Wittgenstein discusses choosing between pictures at §139. That may be, but he does not discuss understanding choosing, which is something that only you have attempted to interject into the discussion. — Luke

So when you describe something, like Wittgenstein describes choosing words at 139 and 140, this is not a case of expressing an understanding of the thing being described? Give me a break.

As I said, there is no such distinction here, and you are grasping for straws to justify your strange assertion, instead of recognizing your misunderstanding of what was written. Go back and read it again, and get back to me when you have something constructive to say.

If meaning is use, and use is described as choosing words, then understanding meaning requires understanding choosing. That's very simple isn't it? And, it's why Wittgenstein discusses choosing words in this section concerning understanding meaning. But if you think that understanding the meaning of a spoken word upon hearing it, is something different from the understanding required to choose words to speak, then you'll recognize the distinction which I said Wittgenstein is blurring. Is Wittgenstein correct to blur this distinction, is it not based in anything real? What about the fact that you can understand spoken words in a flash, but it takes time to choose the words required to properly express what you want to say?

If meaning is use, and use is described as choosing words, then understanding meaning requires understanding choosing. That's very simple isn't it? — Metaphysician Undercover

No, it's convoluted. Where is use described as choosing words? I know it's your presumption, but it's not part of the text.

But if you think that understanding the meaning of a spoken word upon hearing it, is something different from the understanding required to choose words to speak, then you'll recognize the distinction which I said Wittgenstein is blurring. — Metaphysician Undercover

I wasn't specifying this difference; I was noting the distinction you made.

What about the fact that you can understand spoken words in a flash, but it takes time to choose the words required to properly express what you want to say? — Metaphysician Undercover

WIttgenstein doesn't talk about use in mentalistic terms of choosing words. He says only that use is extended in time.

ETA: Wittgenstein talks about mental pictures only to dismiss the idea that meaning is a something in the mind.

No, it's convoluted. Where is use described as choosing words? I know it's your presumption, but it's not part of the text. — Luke

Well, he introduces the topic of what it is to "understand a word" at 138, and proceeds to discuss the meaning of words, the use of words, and the choosing of words. Where's the problem? Why do you insist on excluding the bulk of 139 and 140 where he discusses the choosing of words, claiming it's only my presumption? Or do you think that he is putting the choosing of words into some category other than meaning and use? How could you think this when he explicitly talks about the picture-like thing in the mind, "forcing" upon us a particular use, when we might actually choose the word to mean something else? We have the three elements right here, clear as day in 140, choice, which leads to use, and therefore meaning

WIttgenstein doesn't talk in mentalistic terms of choosing words. He says only that use is extended in time. — Luke

OK, I give up. Where did you get this crazy idea from? Get back to me after you've actually read 139 and 140. The whole section, from here to 200, is full of "mentalistic terms", so I suggest you prepare yourself if you wish to continue.

Well, he introduces the topic of what it is to "understand a word" at 138, and proceeds to discuss the meaning of words, the use of words, and the choosing of words. Where's the problem? Why do you insist on excluding the bulk of 139 and 140 where he discusses the choosing of words, claiming it's only my presumption? — Metaphysician Undercover

Wittgenstein does not mention anything about "choosing words" at 138 or at 140. He makes only a passing mention of choosing words at boxed section (a) of 139, and he makes it only to aid the rejection of meaning as a Something (or a mental picture) in the mind:

Suppose I were choosing between the words “stately”, “dignified”, “proud”, “imposing”; isn’t it as though I were choosing between drawings in a portfolio? — No; the fact that one speaks of the apt word does not show the existence of a Something that... ["a Something that we have in our mind and which is, as it were, the exact picture we want to use here"]

One is inclined, rather, to speak of this picture-like Something because one can find a word apt; because one often chooses between words as between similar but not identical pictures; because pictures are often used instead of words, or to illustrate words, and so on. — PI 139 - Boxed section (a)

What Wittgenstein is saying here is that we are inclined to speak of mental pictures because one can find a word apt, because one often chooses between words as between pictures, etc. However, the inclination to speak in this way does not show the existence of any mental pictures, or that the meaning of a word is a mental picture (i.e. meaning is not "a Something that we have in our mind").

Note however that none of this has anything to do with understanding choosing, and Wittgenstein makes no reference to it. Also, your suggestion that choosing words forms the "bulk" of the discussion at 138-140 is patently false.

Or do you think that he is putting the choosing of words into some category other than meaning and use? How could you think this when he explicitly talks about the picture-like thing in the mind, "forcing" upon us a particular use, when we might actually choose the word to mean something else? — Metaphysician Undercover

His rejection of a mental picture "forcing" a particular meaning/use has nothing to do with choosing words. He makes no mention of choosing words at 140.

We have the three elements right here, clear as day in 140, choice, which leads to use, and therefore meaning — Metaphysician Undercover

Where does he mention choice at 140?

His rejection of a mental picture "forcing" a particular meaning/use has nothing to do with choosing words. — Luke

Let me just see if I can understand your distorted opinion. Wittgenstein is talking about choosing words at 139. Then at 140, where he states the conclusion of his argument of 139, [i.e. that it is impossible that a picture-like thing in the mind forces a particular application, or use on us, because he has shown at 139 that it is possible to use the word in a way other than how the picture would incline one to use the word], he is no longer talking about choosing words.

Please enlighten my so I can understand where I am going wrong. If, in your opinion, he is no longer talking about choosing words here at 140, where he states the conclusion to his argument of 139 (in which he is talking about choosing words), what do you think he is talking about at 140?

140. Then what sort of mistake did I make; was it what we should
like to express by saying: I should have thought the picture forced a
particular use on me? How could I think that? What did I think? Is
there such a thing as a picture, or something like a picture, that forces
a particular application on us; so that my mistake lay in confusing one
picture with another?—For we might also be inclined to express
ourselves like this: we are at most under a psychological, not a logical,
compulsion. And now it looks quite as if we knew of two kinds of
case.
What was the effect of my argument? It called our attention to
(reminded us of) the fact that there are other processes, besides the one
we originally thought of, which we should sometimes be prepared to
call "applying the picture of a cube". So our 'belief that the picture
forced a particular application upon us' consisted in the fact that only
the one case and no other occurred to us. "There is another solution
as well" means: there is something else that I am also prepared to call
a "solution"; to which I am prepared to apply such-and-such a picture,
such-and-such an analogy, and so on.
What is essential is to see that the same thing can come before our
minds when we hear the word and the application still be different.
Has it the same meaning both times? I think we shall say not.

§139, §140

I want to suggest that these sections are an elaboration of §115, in which Witty spoke of being held 'captive by a picture': "And we couldn’t get outside it, for it lay in our language, and language seemed only to repeat it to us inexorably". §139 and §140 suggest the alternative to this 'capture': not, as it were, getting 'beyond' pictures, but recognizing that there are always other pictures which correspond to the use we make of words. Hence the conclusion to §140:

"There are other processes, besides the one we originally thought of, which we should sometimes be prepared to call “applying the picture of a cube”. So our ‘belief that the picture forced a particular application upon us’ consisted in the fact that only the one case and no other occurred to us. “There is another solution as well” means: there is something else that I’m also prepared to call a “solution”, to which I’m prepared to apply such-and-such a picture, such-and-such an analogy, and so on."

It is important to note here that this insight comes right after Witty's extended discussion of comparing langauge-games, of putting them side-by-side to bring out the specificity of each one. (Recall §130: "Rather, the language-games stand there as objects of comparison which, through similarities and dissimilarities, are meant to throw light on features of our language"). It is this method of comparison, recommended by Witty, that allows one to break the 'capture' of a single picture, and recognise the multitude of possible 'pictures' that correspond to various uses.

Working backwards a bit, the discussion in §139 is meant to bring out that there are no meanings 'before' uses which uses then somehow simply modify or alter (another way to say that meaning is use, they are identified with each other). It's not that there is a meaning of a word, which then subsequently fits (or not) its use. There is only use, and the meaning which issues from that use. All of this also further accounts for the various ways in which we are 'mislead by grammar'; skipping forward again to §140: "What is essential now is to see that the same thing may be in our minds when we hear the word and yet the application still be different" - just because we hear the same word doesn't mean that its application is the same. When we miss this, we are led into linguistic malaise.

Since you asked so nicely, here is part of Baker and Hacker's exegesis of 140:

The illusion that a picture forces an application on us merely reflects the fact that by habit and training only one application is naturally suggested to us. If, however, the same mental image occurs to us in relation to different applications, we will not claim that the word has the same meaning despite its different applications. Consequently, the meaning of a word is not a picture in the mind, nor any other entity, and grasping the meaning of a word at a stroke does not consist in having such a picture come before one’s mind.

I think you could be conflating the use (or speaking) of words with choosing words. At least, that's the only reason I can imagine for why you might think Wittgenstein is discussing choice at 140. The use of words that Wittgenstein is talking about in these (and possibly all) sections of the book is a physical expression, not some mental decision making process. If I'm mistaken, then you are still welcome to explain where Wittgenstein is talking about choosing words (or understanding choosing) at 140.

Actually, reading a bit closer and prompted by @Luke's quote, I want to make an amendment to what I wrote above. I think I was wrong to speak of pictures in the multiple. What's at stake is not 'one picture as opposed to a different picture', but different ways to understand the application of a picture. This lines up better with: "there are other processes, besides the one we originally thought of, which we should sometimes be prepared to call “applying the picture of a cube”." In this light, to be held 'captive by a picture' is a shorthand for being captive by one way of applying a picture, and to not recognize the multiplicity of applications of a picture. The application of a picture, in this sense, is differential. Much like, it's worth noting, ostensive definitions, the discussion of which opens the PI, and which are also marked as essentially differential.

In the midst of summarising the current sections and while trying to find more information about Wittgenstein's use of "method of projection", I came across this very good reading of the current sections, which some should find useful. I think it explains the matter better than my attempted summary possibly could.

Also, here is the information I gathered regarding Wittgenstein's "method of projection":

We may say: a blueprint serves as a picture of the object which the workman is to make from it.
And here we might call the way in which the workman turns such a drawing into an artefact "the method of projection". We might now express ourselves thus: the method of projection mediates between the drawing and the object, it reaches from the drawing to the artefact. Here we are comparing the method of projection with projection lines which go from one figure to another. — But if the method of projection is a bridge, it is a bridge which isn't built until the application is made. — This comparison conceals the fact that the picture plus the projection lines leaves open various methods of application...

...what we may call 'picture' is the blueprint plus the method of its application. — Philosophical Grammar (p.213)

With regards to Wittgenstein's cube, it can look like a triangular prism (or vice versa) when viewed from certain angles. Therefore, if we project or apply the picture in a particular way, then the picture of the cube can be made to fit with (or to look like) an actual triangular prism.

This was nice:

"The picture, don't forget, is not being cast as an aid to understanding; it is supposed to be the thing itself. But it's hard to see how it can play that role when it provides no standard of correctness. If this observation seems familiar, that's because it is closely analogous to the point made about ostensive definition in relation to meaning. There, it was supposed that the sample by itself could establish a link between word and object, that it was completely unambiguous and therefore unmistakable. But it turned out that it only functioned as part of an established practice of describing the rule for the use of a word. And it's a very similar story in the case of the picture (which is, after all, a kind of mental sample). We have the sample, but what we lack is the application. (I should also mention that as well as looking back to ostensive definition this point also anticipates aspects of the discussion of rule-following."

I briefly noted the link between Witty's discussion of ostenstive definition and pictures, but it's true that the discussion applies to rules as well. In all three cases - rules, pictures, and ostensive definition - the point is the same: nothing 'in' the rules, or the pictures, or the ostensive gesture, tells us how to apply them. To anticipate a semi-technical term that Witty uses later, what does tell us how to apply these things is a technique, or rather, a mastery of a technique, which is informed by our forms-of-life. Incidentally, this is brought out in the second part of the boxed note in §139 (b.), where Witty speaks of the Martain looking at the picture of the old man on the hill. Whether the man is going up or down - this is not 'given' by the picture. What the man is doing, what the picture represents, is 'given' only by how we engage with it.

I think you could be conflating the use (or speaking) of words with choosing words. — Luke

Call it conflation if you like, but when a person speaks words, if the array of words which one speaks is not "forced" upon that person by a mental image or some such thing, then the person is "choosing words. So, by Wittgenstein' description, speaking words, and choosing words are one and the same thing, because the application is not "forced" on us. That is the point of 139. The mental image (picture) of a cube suggests a certain use of "cube" to me, but I might still use the word in a completely different way.

The use of words that Wittgenstein is talking about in these (and possibly all) sections of the book is a physical expression, not some mental decision making process. — Luke

He is clearly talking about the mental process here. He started by describing a mental picture-like thing, which would "force" our word usage. He has dismissed this as inaccurate, because it is possible to use a word in a way other than the way which would be forced by the picture-like thing. He has not dismissed the mental process, he has just dismissed the "forcing". So he will continue to discuss the mental process at 141 "Suppose, however, that not merely the picture of the cube, but also the method of projection comes before our mind?".

If I'm mistaken, then you are still welcome to explain where Wittgenstein is talking about choosing words (or understanding choosing) at 140. — Luke

It's very obvious, the footnote of 139 clearly describes choosing words, and the conclusion of 139 is a statement of choosing to use the word "cube" in a way other than that suggested by the picture. So he proceeds into 140 saying that it is not a case of the mental picture-like thing forcing a use on us. If you have truly read these sections, and paid attention to what I've explained, yet you still do not see that he is talking about choosing words (despite the fact that he explicitly talks about choosing words in the footnote), then I'm afraid I may not be able to help you further.

What's at stake is not 'one picture as opposed to a different picture', but different ways to understand the application of a picture. This lines up better with: "there are other processes, besides the one we originally thought of, which we should sometimes be prepared to call “applying the picture of a cube”." In this light, to be held 'captive by a picture' is a shorthand for being captive by one way of applying a picture, and to not recognize the multiplicity of applications of a picture. — StreetlightX

At 139, the application of the picture is the act of selecting the word for use. The point being that the picture of a cube may occur in my mind every time I hear the word "cube", but we cannot say that a person applies the picture when saying the word "cube" (selecting the word "cube" for use), because I might "point to a triangular prism for instance, and say it is a cube". Hence the footnote about choosing the appropriate word, and the conclusion of 139: "The picture of the cube did indeed suggest a certain use to us, but it was possible for me to use it differently."

So, he proceeds onward at 140 to discuss the outcome of 139. The picture-like thing is what is supposed to come to mind when we hear the word, and as described at the beginning of 139, there may be many different ones associated with the same word, due to different uses of that word. Now the issue at the end of 139 is that I may choose to use the word in a completely different way, distinct from all these pictures derived from all these other uses. The conclusion therefore, expressed at 140, and expounded on at 141, is that the process whereby words are used (we speak and write), "the application", is something other than a case of applying a picture-like thing, or whatever it is which comes to your mind when you hear the word. Hence your quoted line "there are other processes, besides the one we originally thought of, which we should sometimes be prepared to call 'applying the picture of a cube'". And the conclusion of 140 "What is essential is to see that the same thing can come before our minds when we hear the word and the application still be different." [Application being one's use of the word, in the sense of "belief that the picture forced a particular application upon us".] So he proceeds at 141 to question this method of application, which I called choosing words, but Luke doesn't like that terminology.

§139, Boxed Note, (a)

This note brings out the stakes of §139 quite nicely I think, and I want to try and consider both together. What seems to be at issue is the idea that 'before' use, there are meanings (of words), and the point is to try and find a use that fits the meaning we have in mind. Hence the idea of trying to pick an 'apt word', a word that would 'fit' the idea that we had in mind. But Witty argues that this gets things exactly the wrong way around; it's not that first we have an idea of what we want to mean, and then we find a word that fits it; rather, it's because certain words are more apt than others, do we get an idea of what we want to say: "the fact that one speaks of the apt word does not show the existence of a Something that . . . One is inclined, rather, to speak of this picture-like Something because one can find a word apt".

This reads nicely with Witty's setting up of the 'two-stages' of meaning in §139, only to then subsequently undo it. Note that he speaks, in §139, of multiple (two) ways of determining meaning: "On the other hand, isn’t the meaning of the word also determined by this use? And can these ways of determining meaning conflict?" (my emphasis). In this light, §139 is an attempt to show that there is no two-stage process, but only the one. To conjure up a 'picture of a cube' is to already have an application of it in mind. It may not be the only application there is ("it was also possible for me to use it differently"), but this doesn't imply that there are two stages from meaning to application. Rather, the application is always-already inherent to the meaning.

:up:

...by Wittgenstein' description, speaking words, and choosing words are one and the same thing... — Metaphysician Undercover

Thanks for clearing that up. Could you now explain your earlier distinction between ""understanding" in the sense of understanding a spoken word, and "understanding" in the sense required to choose a word in speaking"? If speaking and choosing words are one and the same according to Wittgenstein, then why should there be two different types of understanding here?

§141

I mentioned above that what is being said here of pictures also applies to rules. This section in particular brings that similarity out, especially when placed side-by-side with §86. To recap, §86 was about how to read charts, how rules related to the reading of charts. There, Witty produced what he called a 'schema' - a literal picture of arrows - that counted as a rule for the use of the chart. At the end of it, he goes on to ask, rhetorically: "Can we not now imagine further rules to explain this one?" - the implication being that how one applies rules is not to be found in rules themselves.

Bringing this back to §141, a similar argumentative strategy is at work here, with Witty even reusing the vocabulary of 'schemas'. Speaking here of a "schema showing the method of projection [for a picture]", Witty effectively asks whether this schema is enough to guarantee that a picture is applied in any particular way. And just as in §86, Witty's answer is no: one can well "imagine different applications of this schema".

Once again though, Witty looks to 'test' his account to check if there is, in fact, a two-stage process at work, which he ultimately wants to deny. As he puts it, it looks as though there were first the picture, then its application ("On the one hand, the picture ... on the other, the application which ... he makes of this image"). And moreover, it looks like the picture and the application can 'clash'. Doesn't this attest to a 'fit' and not a 'belonging' (to use the vocabulary of §136)? Witty's answer is no: what 'clashes' is a picture and one application of it, with a picture and another application of it: "they can clash in so far as the picture makes us expect a different use; because people in general apply this picture like this."

Finally, though I won't elaborate on it too much, one ought to also hear resonances with Witty's discussion of the meter rule here. Just as the meter rule plays (or does not play) a role in a language-game, so too does the application of a picture play - or not - a role in a language-game. More to be said, but I leave it to one to consider the connections.

§142

This one's quite straight-forward, so I want to try and maybe couch it in different terms: language-game require certain things to stay constant. Speaking in terms of a meter-rule only make sense if what counts as a meter stays roughly constant through our uses; similarly, it only makes sense if the things we do with the meter-rule stay the same - one can't speak of 'measuring' while using the rule to both measure and to hit something. 'Measuring' would 'lose it's point'.

It'd be like trying to do math when the values and operators fluctuate constantly, with pluses replacing minuses, and powers appearing and disappearing at will. One would be unable to use the equations for anything. It wouldn't even be math.

And with the above, we're at the start of (what I think is) another new section! If I may recap, here's my idiosyncratic breakdown of what's been covered so far (bold for where we're going next):

§1-§27: Imperatives (block! slab!)
§28-§36: Demonstratives (this, that)
§37-§45: Names (Nothung, Mr. N.N.)
§46-§64: Linguistic Roles (Simples, Composites, and Iterations thereof)
§65-§80: Definitions and Boundaries
§81-88(?): Idealizations of/in Language
§88-133: Philosophy and Explanation (Or, Theses and Descriptions)
§134-142: Use: Belonging and Fitting
§143-§198: Understanding, Reading, and Learning (groundwork for rule-following discussions)

The 'little' section we just went over acts as something like a 'bridge' between Witty's discussion of philosophy and the subsequent discussion of understanding, etc. The 'bridge' can be said to span questions regarding being 'captured by a picture' (from the previous section), and introduces questions of how 'application' occurs. The next section (another long one) takes off from the question of application. I quite like what's coming up, and it's very useful - IMO - to read it as also laying down the groundwork for what comes after it - the famous discussions on rule-following. As we read through the next bit, it might be useful to keep that in mind, even as 'rules' will not come up all that often.

Thanks for clearing that up. Could you now explain your earlier distinction between ""understanding" in the sense of understanding a spoken word, and "understanding" in the sense required to choose a word in speaking"? If speaking and choosing words are one and the same according to Wittgenstein, then why should there be two different types of understanding here? — Luke

Suppose you hear a spoken word, and understanding that word consists of associating it with a picture like thing (I will call it an "idea", perhaps). Now, speaking is using words, what Wittgenstein calls "application". If we simply reverse the process above, and say that choosing the appropriate word for use is simply a matter of applying that idea, to determine the appropriate word, we have the problem brought up at 139. As much as the idea associated with "cube" tends to force a certain use on me, I can still use the word to refer to a prism if I want. Therefore, as Wittgenstein concludes at 140, there must be another process, or other processes involved in choosing which words to use, distinct from the process of associating the word with ideas, which we often assume accounts for the "understanding" of the spoken word. That is why I referred to this other process whereby we choose words to be spoken as a distinct form of "understanding".

This reads nicely with Witty's setting up of the 'two-stages' of meaning in §139, only to then subsequently undo it. Note that he speaks, in §139, of multiple (two) ways of determining meaning: "On the other hand, isn’t the meaning of the word also determined by this use? And can these ways of determining meaning conflict?" (my emphasis). In this light, §139 is an attempt to show that there is no two-stage process, but only the one. To conjure up a 'picture of a cube' is to already have an application of it in mind. It may not be the only application there is ("it was also possible for me to use it differently"), but this doesn't imply that there are two stages from meaning to application. Rather, the application is always-already inherent to the meaning. — StreetlightX

It ought to be mentioned that at 141-142 Wittgenstein distinguishes a normal way from an abnormal way of using words. The normal way is the more direct application of the picture [idea] to the word, and this leaves little doubt in the word selection process. This would be the person's habitualized idea/word association, implying a direct relationship between mental activity and word, by psychological necessity (not logical necessity). The abnormal way is the other process, or processes, which Wittgenstein has declared necessary by his argument at 139 to account for the reality of (more random) word selection, by which words are chosen by a means other than a direct application of ideas.

I am very critical of this classification, because I would class such a direct application of idea - word as abnormal, and the more complex selective process as normal. Witty's argument at 142, is that if the direct application were not the normal way, then our language games would lose their point. However, until this point, he has been arguing that the essence of language, and therefore language-games, is their vague, unbounded, ambiguous character. So to place the direct association of the idea to the word, as the "norm" here, is completely inconsistent. Though he might be using "norm" in a different way, implying at 142 that the "prescribed" way is the norm. The problem being that he has yet to establish any basis for a "prescribed" way, therefore the normal way must still be the vague and ambiguous, natural way to maintain consistency .

Suppose you hear a spoken word, and understanding that word consists of associating it with a picture like thing (I will call it an "idea", perhaps). Now, speaking is using words, what Wittgenstein calls "application". If we simply reverse the process above, and say that choosing the appropriate word for use is simply a matter of applying that idea, to determine the appropriate word, we have the problem brought up at 139. — Metaphysician Undercover

The "problem brought up at 139" is problematic for both the hearing and the speaking of a word, due to the erroneous assumption that meaning is a picture in the mind. This is the upshot of the current sections.

As much as the idea associated with "cube" tends to force a certain use on me, I can still use the word to refer to a prism if I want. — Metaphysician Undercover

The point here is that your mental picture of a cube can be made to fit with a prism; or, that the mental picture can have the application of a prism via a particular method of projection. On the other hand, if the mental picture stood for the meaning of the word, then the cube could not be made to fit with the prism, or it could not have that application. Again, this is to reveal the problems with the assumption that meaning is a picture in the mind. However, it should not be inferred from this that you can use a word to mean whatever you want.

Therefore, as Wittgenstein concludes at 140, there must be another process, or other processes involved in choosing which words to use, distinct from the process of associating the word with ideas, which we often assume accounts for the "understanding" of the spoken word. That is why I referred to this other process whereby we choose words to be spoken as a distinct form of "understanding". — Metaphysician Undercover

Again, understanding a spoken word does not necessarily consist of "associating it with a picture like thing" either, so I dispute your distinction between two types of understanding.

However, it should not be inferred from this that you can use a word to mean whatever you want. — Luke

I don't see why not. It's not that you use the word to mean something, because meaning and use are one and the same. If you use a word, the word has meaning by the fact that it was used. And the meaning is based on the way the word was used. So, you can use a word however you please, and this use provides meaning for that word. There is absolutely nothing to force any particular use, nor has Wittgenstein described anything which would restrict the application of the word. Therefore I see no reason for the conclusion you have made.

"The picture of the cube did indeed suggest a certain use to us, but it was possible for me to use it differently."

If it is always possible to use the word differently from what is suggested, then what could restrict the number of different uses which a word could have, and why could you not use a word however you wanted, thereby forcing the pertinent meaning on the word by virtue of that use?

Again, understanding a spoken word does not necessarily consist of "associating it with a picture like thing" either, so I dispute your distinction between two types of understanding. — Luke

Well, this is the only form of understanding a spoken word which Wittgenstein has described, associating the word with a picture-like thing. He does refer to another process, but this is in describing application, using, or speaking words. So we have no reference to any other form of understanding a spoken word, only a reference to another type of process (understanding) involved in speaking words. What is pointed to is that there is one type of understanding involved with hearing words, and another type involved with speaking words.

This is the weakness of his argument. He starts with a proposition about understanding a word, either hearing or speaking it. This is the proposition of associating the word with a picture-like thing. He criticizes that proposition through reference to the process of speaking words, application. But he provides no evidence that such a criticism would be relevant to understanding in the sense of hearing a word. So all he has done is demonstrated a division between hearing words and speaking words, revealing that these are two distinct processes. This difference ought to be evident to anyone who has thought about it anyway. But, the claim that Wittgenstein has proven that understanding a spoken word is not a matter of associating it with a picture-like thing, is unsupported, for this reason, it requires the conflation of hearing and speaking, which Wittgenstein has actually driven a wedge between.

Just to clarify my last point Luke, hearing a word and speaking a word are not the same thing, they are distinct processes. Wittgenstein's argument against the proposition that understanding a word is a matter of associating it with a mental picture-like thing, is based solely on the process of speaking words. We have no principle by which we can apply this conclusion toward the process of hearing words. So there is no argument against the proposition that understanding a spoken word (hearing a word) is a matter of associating it with a mental picture-like thing.

"The picture of the cube did indeed suggest a certain use to us, but it was possible for me to use it differently."

If it is always possible to use the word differently from what is suggested, then what could restrict the number of different uses which a word could have, and why could you not use a word however you wanted, thereby forcing the pertinent meaning on the word by virtue of that use? — Metaphysician Undercover

It is possible for the meaning/use of the word to be different from what is suggested by the mental picture which is evoked when you hear or say the word. Thus, meaning is not a mental picture. This does not mean that anything goes; there are other constraints. Otherwise, elephant of cheese red line upon whiskey very distance. Understand?

This is the weakness of his argument. He starts with a proposition about understanding a word, either hearing or speaking it. This is the proposition of associating the word with a picture-like thing. He criticizes that proposition through reference to the process of speaking words, application. But he provides no evidence that such a criticism would be relevant to understanding in the sense of hearing a word. — Metaphysician Undercover

What we understand is the meaning of the word(s), right? If meaning is not a mental picture, then this applies equally to words spoken and words heard. Do you agree that Wittgenstein demonstrates that meaning is not a mental picture? Or do you still fail to comprehend even the most basic insights of the text?

What is essential now is to see that the same thing may be in our minds when we hear the word and yet the application still be different. Has it the same meaning both times? I think we would deny that. — PI 140

It is possible for the meaning/use of the word to be different from what is suggested by the mental picture which is evoked when you hear or say the word. Thus, meaning is not a mental picture. This does not mean that anything goes; there are other constraints. Otherwise, elephant of cheese red line upon whiskey very distance. Understand? — Luke

If the appropriate picture is not associated when hearing the word, this is not understanding, we call it misunderstanding. But speaking the word is completely different. As Wittgenstein demonstrates, the use of the word [and speaking the word is the use of the word, hearing is not using the word] is not constrained in this way. The problem you mention is brought up at 142. There is normal usage, and abnormal usage. "Normal" usage, as "prescribed" usage, prevents such problems.

What we understand is the meaning of the word(s), right? — Luke

I would prefer to say that what we understand is the use of the words. Do you agree with this?

If meaning is not a mental picture, then this applies equally to words spoken and words heard. Do you agree that Wittgenstein demonstrates that meaning is not a mental picture? — Luke

The problem is that speaking a word is using a word, hearing a word is not. To understand the meaning of a heard word is to understand its use, i.e. how it was used by the speaker. What Wittgenstein demonstrates is that there are no such constraints on the user of the word (speaker).

Meaning is use, and use is not a mental picture, it is an activity. So the fact that meaning is not a mental picture is self-evident from the premise that meaning is use. However, Wittgenstein has provided nothing as of yet, to demonstrate that understanding the meaning of a spoken word (understanding its use), is not a matter of associating the word with a mental picture. He proceeds to demonstrate at 141, how the application of words (use) may be carried out simply as a process, without any mental picture associated with the words, but I think it's questionable whether such use would be intelligible. It may be something like this: "elephant of cheese red line upon whiskey very distance".

In your quoted passage, ("What is essential now is to see that the same thing may be in our minds when we hear the word and yet the application still be different."), what is important is to notice that "application" of the word, or use of the word, speaking it, is distinct from hearing the word. Otherwise you will not grasp what Wittgenstein is saying. What we call "understanding" the word, may very well be our capacity to associate it with the appropriate mental picture. However, application of the word, our use of it in speaking, need not be consistent with our "understanding" of it, and this produces "abnormal use". My point, is that unless such use (abnormal) is completely random, there must be another type of understanding to account for this use of the word (speaking), which is not consistent with the above "understanding", but is nevertheless not random. This will come up in the following sections when Wittgenstein discusses the difference between a systematic mistake, and a random mistake ("mistake" being the usage which is inconsistent with the normal).

What we understand is the meaning of the word(s), right?
— Luke

I would prefer to say that what we understand is the use of the words. Do you agree with this? — Metaphysician Undercover

Sure, meaning is use.

To understand the meaning of a heard word is to understand its use, i.e. how it was used by the speaker. What Wittgenstein demonstrates is that there are no such constraints on the user of the word (speaker). — Metaphysician Undercover

A speaker doesn't require any understanding in their use of words? Where does Wittgenstein demonstrate this?

Meaning is use, and use is not a mental picture, it is an activity. So the fact that meaning is not a mental picture is self-evident from the premise that meaning is use. However, Wittgenstein has provided nothing as of yet, to demonstrate that understanding the meaning of a spoken word (understanding its use), is not a matter of associating the word with a mental picture. He proceeds to demonstrate at 141, how the application of words (use) may be carried out simply as a process, without any mental picture associated with the words, but I think it's questionable whether such use would be intelligible. It may be something like this: "elephant of cheese red line upon whiskey very distance". — Metaphysician Undercover

How is it unintelligible given your claim that "you can use a word however you please, and this use provides meaning for that word"? I used those words however I pleased, therefore I must have provided meaning for those words. So what makes it unintelligible?

§142, Boxed Note

Forgot about this one. Anyway, recalling that §142 remarks that language-games only work if certain constants or invariants are in place, the boxed note here can be read as qualifying the scope of these invariants, which are "often extremely general facts of nature ... hardly ever mentioned because of their great generality". Witty doesn't give any specific examples of such facts, but some of the things mentioned in §142 proper hint at what he's getting at:

"And if things were quite different from what they actually are —– if there were, for instance, no characteristic expression of pain, of fear, of joy .... our normal language-games would thereby lose their point ... The procedure of putting a lump of cheese on a balance and fixing the price by the turn of the scale would lose its point if it frequently happened that such lumps suddenly grew or shrank with no obvious cause."

So: we measure things; we express emotions and affects - 'general facts', too obvious to mention most of the time. To anticipate a little, Witty will largely go on to imply that these 'general facts' have to do with our being human. §142 mentions that "This remark will become clearer when we discuss such things as the relation of expression to feeling, and similar topics."; Licensed by this, I just wanna quote a pair of characteristic remarks on this from way further down:

§281: "Only of a living human being and what resembles (behaves like) a living human being can one say: it has sensations; it sees; is blind; hears; is deaf; is conscious or unconscious".

§415: "What we are supplying are really remarks on the natural history of human beings; not curiosities, however, but facts that no one has doubted, which have escaped notice only because they are always before our eyes."

I think it's useful to keep these remarks (and others like it, scattered throughout the PI later) in mind as we read this.