Wittgenstein LudwigLectures On Philosophy.docx

1、Wittgenstein Ludwig Lectures On PhilosophyLudwig Wittgenstein (1932-33)Lectures on PhilosophySource: Wittgensteins Lectures, 1932 - 35, Edited by Alice Ambrose, publ. Blackwell, 1979. The 1932-33 Lecture notes, pp2 - 40 reproduced here.Due to the limitations of HTML, I have used the following charac

2、ters to represent symbols of mathematical logic: for is a super set of, for is a subset of, for not, for there is, v for or, . for and1 I am going to exclude from our discussion questions which are answered by experience. Philosophical problems are not solved by experience, for what we talk about in

3、 philosophy are not facts but things for which facts are useful. Philosophical trouble arises through seeing a system of rules and seeing that things do not fit it. It is like advancing and retreating from a tree stump and seeing different things. We go nearer, remember the rules, and feel satisfied

4、, then retreat and feel dissatisfied.2 Words and chess pieces are analogous; knowing how to use a word is like knowing how to move a chess piece. Now how do the rules enter into playing the game? What is the difference between playing the game and aimlessly moving the pieces? I do not deny there is

5、a difference, but I want to say that knowing how a piece is to be used is not a particular state of mind which goes on while the game goes on. The meaning of a word is to be defined by the rules for its use, not by the feeling that attaches to the words.How is the word used? and What is the grammar

6、of the word? I shall take as being the same question.The phrase, bearer of the word, standing for what one points to in giving an ostensive definition, and meaning of the word have entirely different grammars; the two are not synonymous. To explain a word such as red by pointing to something gives b

7、ut one rule for its use, and in cases where one cannot point, rules of a different sort are given. All the rules together give the meaning, and these are not fixed by giving an ostensive definition. The rules of grammar are entirely independent of one another. Two words have the same meaning if they

8、 have the same rules for their use.Are the rules, for example, p = p for negation, responsible to the meaning of a word? No. The rules constitute the meaning, and are not responsible to it. The meaning changes when one of its rules changes. If, for example, the game of chess is defined in terms of i

9、ts rules, one cannot say the game changes if a rule for moving a piece were changed. Only when we are speaking of the history of the game can we talk of change. Rules are arbitrary in the sense that they are not responsible to some sort of reality-they are not similar to natural laws; nor are they r

10、esponsible to some meaning the word already has. If someone says the rules of negation are not arbitrary because negation could not be such that p =p, all that could be meant is that the latter rule would not correspond to the English word negation. The objection that the rules are not arbitrary com

11、es from the feeling that they are responsible to the meaning. But how is the meaning of negation defined, if not by the rules? p =p does not follow from the meaning of not but constitutes it. Similarly, p.p q. .q does not depend on the meanings of and and implies; it constitutes their meaning. If it

12、 is said that the rules of negation are not arbitrary inasmuch as they must not contradict each other, the reply is that if there were a contradiction among them we should simply no longer call certain of them rules. It is part of the grammar of the word rule that if p is a rule, p.p is not a rule.3

13、 Logic proceeds from premises just as physics does. But the primitive propositions of physics are results of very general experience, while those of logic are not. To distinguish between the propositions of physics and those of logic, more must be done than to produce predicates such as experiential

14、 and self-evident. It must be shown that a grammatical rule holds for one and not for the other.4 In what sense are laws of inference laws of thought? Can a reason be given for thinking as we do? Will this require an answer outside the game of reasoning? There are two senses of reason: reason for, a

15、nd cause. These are two different orders of things. One needs to decide on a criterion for somethings being a reason before reason and cause can be distinguished. Reasoning is the calculation actually done, and a reason goes back one step in the calculus. A reason is a reason only inside the game. T

16、o give a reason is to go through a process of calculation, and to ask for a reason is to ask how one arrived at the result. The chain of reasons comes to an end, that is, one cannot always give a reason for a reason. But this does not make the reasoning less valid. The answer to the question, Why ar

17、e you frightened?, involves a hypothesis if a cause is given. But there is no hypothetical element in a calculation.To do a thing for a certain reason may mean several things. When a person gives as his reason for entering a room that there is a lecture, how does one know that is his reason? The rea

18、son may be nothing more than just the one he gives when asked. Again, a reason may be the way one arrives at a conclusion, e.g., when one multiplies 13 x 25. It is a calculation, and is the justification for the result 325. The reason for fixing a date might consist in a mans going through a game of

19、 checking his diary and finding a free time. The reason here might be said to be included in the act he performs. A cause could not be included in this sense.We are talking here of the grammar of the words reason and cause: in what cases do we say we have given a reason for doing a certain thing, an

20、d in what cases, a cause? If one answers the question Why did you move your arm? by giving a behaviouristic explanation, one has specified a cause. Causes may be discovered by experiments, but experiments do not produce reasons. The word reason is not used in connection with experimentation. It is s

21、enseless to say a reason is found by experiment. The alternative, mathematical argument or experiential evidence? corresponds to reason or cause?5 Where the class defined by f can be given by an enumeration, i.e., by a list, (x)fx is simply a logical product and (x)fx a logical sum. E.g., (x)fx.=.fa

22、.fb.fc, and (x)fx.=.fa v fb v fc. Examples are the class of primary colours and the class of tones of the octave. In such cases it is not necessary to add and a, b, c, . . . are the only fs The statement, In this picture I see all the primary colours, means I see red and green and blue . . ., and to

23、 add and these are all the primary colours says neither more nor less than I see all . . .; whereas to add to a, b, c are people in the room that a, b, c are all the people in the room says more than (x)x is a person in the room, and to omit it is to say less. If it is correct to say the general pro

24、position is a shorthand for a logical product or sum, as it is in some cases, then the class of things named in the product or sum is defined in the grammar, not by properties. For example, being a tone of the octave is not a quality of a note. The tones of an octave are a list. Were the world compo

25、sed of individuals which were given the names a, b, c, etc., then, as in the case of the tones, there would be no proposition and these are all the individuals.Where a general proposition is a shorthand for a product, deduction of the special proposition fa from (x)fx is straightforward. But where i

26、t is not, how does fa follow? Following is of a special sort, just as the logical product is of a special sort. And although (x)fx.fa. =.fa is analogous to p v q.p. =.p, fa follows in a different way in the two cases where (x)fx is a shorthand for a logical sum and where it is not. We have a differe

27、nt calculus where (x)fx is not a logical sum fa is not deduced asp is deduced in the calculus of Ts and Fs from p v q.p. I once made a calculus in which following was the same in all cases. But this was a mistake.Note that the dots in the disjunctions v fb v fc v . . . have different grammars: (1) a

28、nd so on indicates laziness when the disjunction is a shorthand for a logical sum, the class involved being given by an enumeration, (2) and so on is an entirely different sign with new rules when it does not correspond to any enumeration, e.g., 2 is even v 4 is even v 6 is even . . ., (3) and so on

29、 refers to positions in visual space, as contrasted with positions correlated with the numbers of the mathematical continuum. As an example of (3) consider There is a circle in the square. Here it might appear that we have a logical sum whose terms could be determined by observation, that there is a

30、 number of positions a circle could occupy in visual space, and that their number could be determined by an experiment, say, by coordinating them with turns of a micrometer. But there is no number of positions in visual space, any more than there is a number of drops of rain which you see. The prope

31、r answer to the question, How many drops did you see?, is many, not that there was a number but you dont know how many. Although there are twenty circles in the square, and the micrometer would give the number of positions coordinated with them, visually you may not see twenty.6 I have pointed out t

32、wo kinds of cases (I) those like In this melody the composer used all the notes of the octave, all the notes being enumerable, (2) those like All circles in the square have crosses. Russells notation assumes that for every general proposition there are names which can be given in answer to the question Which ones? (in contrast to, What sort?). Consider (x)fx, the notation for There are men on the island and for There is a circle in the square.Now in the case of human beings, where we use names, the question Which