What did Wittgenstein mean by the next day's weather cannot be inferred?

So here's this bit from phailsophy bros Wittgenstein- <br><br>***<br><br>Let us now imagine a game played out in a world in which mirrors, photographs, and similar apparatus have no place. And now we will throw in the question of whether the scientist could find a law determining the succession of phenomena in the game played in *this world.* He will either find none, or else such a law will appear to him to be a triviality. And what scientists do is not so irrelevant to the concept of language as the thought of Superian might make it appear.<br><br><br><br>Consider, for example, the procedure of forming an estimate of the quantity—"American standard quantity"—of milk. The method used is this. Without making any measurement, you take a sample *at random out of the morning's supply, pour it into a bottle, and seal it. And then, if anybody asks how much milk was delivered, say: "American standard quantity." Or again. You give someone's height ("height in Philadelphia") as equal to the height of the standard man in Philadelphia as ascertained at noon Cord. by measuring him (if he is alive). But to be quite exact, you ought, logically, not to measure him; for *his height varies slightly, and so it is misleading if you say that he is six feet tall and not: he is six feet tall *now* (and perhaps not any longer by the time I have finished the sentence). But you take the height of the man in Philadelphia at noon today simply as the standard of height, giving somebody else's height by saying: "he is *as* tall as A. in Philadelphia at noon today." If you are asked how many millimeters his height amounts to in absolute measure, you reply: "I don't know; but I do know that he is as tall as A. is in Philadelphia at noon today."<br><br><br><br>The next day, you can again determine how tall he is by saying that he is as tall as B. is today in Philadelphia at noon. *But this will not necessarily be the same as yesterday's height*<br><br><br><br>Is it clear that it is possible to proceed in this way? And is it also clear that this is a perfectly good method of determining height—apart from the fact that it will not produce any specially interesting results? So what, you will ask, is the point of proceeding in this way? Well, it is clear that the scientists would never bother with this, as being too unimportant. But what is unimportant for the scientist is still an *interesting* method for the philosopher. For the scientist looks for important propositions, and hence, as we have seen, sometimes for *trivialities.* But sometimes what he is after can be attained only by means of trivialities,<br><br><br><br> mirrors tell us whether it is raining outside in the garden—<br><br>but a parasol, an open door, or a raincoat may also do so. And, similarly, the proposition about the weather may serve as information as well as serving as a tautology. So what a scientist will do is this. He will give a tautology as a piece of information only if, in conjunction with other data, it *determines* an interesting proposition. For example, he will determine the quantity of a delivered gas by the volume of the container, together with Boyle's law, if this enables him to infer the pressure of the gas. *But the fact that the container was full of gas yesterday is not going to be of any interest to him;* and it is perfectly right and proper that it should not interest him. For what *he is after* are *important propositions* and these can be obtained by the use of tautologies only if they are combined with other propositions. So for the scientist there is no such thing as "pure description." Yet description, "pure description," has *its own interest*, even if this is not of any importance for the scientist.<br><br><br><br>The general propositions of science are "tautologies." For example: "water boils at 100 C." is a tautology. <br><br> "At 0 C. water is solid, at 100 C. it is gaseous. And so in between it is liquid." That is a tautology. But the statement "This body melts at 0 C." is by no means a tautology. On the contrary, it took 100 years to discover that water did this. But if it were to melt at 100 C. and be liquid at 0 C., we simply would not call it water. But what *kind* of proposition is: "butter melts at about 37 C."? It cannot be deduced from our definitions—<br><br>but is it an experimental proposition? Can one imagine any experiment which would show that butter did not melt at 37" C.? On the contrary, whatever butter did at 37 C. would be called melting. *This proposition is in fact a grammatical proposition,* so of course it cannot be deduced from the grammatical proposition which tells us what "butter" means by itself. But why does it surprise us if someone were to say that water boils below 0 C. or that ice is liquid? Because this is not in accord with the grammar of the word "water." But does it then mean that the grammar of the word "water" *forbids* water to boil at anything except 100 C.? Does it mean that it is *unthinkable* that water should boil at 50 C.? Nothing is unthinkable. But elementary experimentation has taught us that water does boil at 100 C. This is the grammatical rule for the word "water." So it is a grammatical proposition and *not* an empirical one.<br><br><br><br>- LW