The third approach was analytical. Through the examination of pure concepts, we can gain significant knowledge of things. According to KantÆs predecessor Wolff, there are two principles of metaphysical knowledge. The principle of non-contradiction says that what contains a contradiction is impossible and cannot exist. A square circle would be an example. The principle of sufficient reason states that whatever exists does so because there is a reason sufficient to bring about its existence. Wolff thought that if such a reason did not exist, a contradiction would result.
Hume and Kant rejected this approach as well. Hume took a skeptical line. The law of non-contradiction can given knowledge only of relations of ideas, not matters of fact. The principle of sufficient reason would give us such knowledge, but we cannot justify it rationally. Its use is merely a matter of custom and habit. Kant claimed that we can use the principle of sufficient reason with justification, but only in the restricted realm of experience. It is an a priori principle, meaning that it is not derived from experience but serves instead as a principle that makes experience possible.
Now we shall see how the early Wittgenstein (i.e. the Wittgenstein of the Tractatus) approached these issues. Like Hume and Kant, Wittgenstein denied that there is any rational intuition. Reason is restricted to is logical use. Indeed, language, which contains logic, is the limit of human thought. So what we know through the use of thought, what we know rationally, is not through intuition.
As far as the unconditioned is concerned, WittgensteinÆs view was not uniform. He believed that the world is made of objects which are simple. The objects are the ultimate parts constituting states of affairs. Kant had denied that there is knowledge of anything simple. For Hume there are simples, i.e., simple ideas, but these are merely psychological, not constituents of the reality of all things.
On the other hand, Wittgenstein believed that reason cannot transcend the things of the world. That is, we can conceive of many possible worlds, which are many different configurations of objects. But there is no ultimate explanation of why the actual world, rather than any of the other worlds, is actual. It just is, as a matter of brute fact. Contrast this with the view of Leibniz (17th-18th century), who held that this world is actual because it is the best possible world, which is the one that must be chosen by the creator, God. This kind of inference to the unconditioned has no place in WittgensteinÆs system.
The other approach is analytical rationalism. Here it seems that Wittgenstein was siding with Hume and against Kant. He denied that there is any a priori element in experience. The use of induction is merely a matter of convenience. To infer that what is unobserved will follow the same patterns as what has been observed is merely a simplifying assumption.
But Wittgenstein departed from HumeÆs view in a crucial respect, concerning ethics. According to Hume, ethical values are to be found in the psychology of the human being, in feelings or sentiments. Part of what makes acts good or bad is the pleasure or pain they carry with them. But for Wittgenstein, the state of the world, including all human psychological states, are irrelevant to ethical values. The banishment of moral values from the world is of a piece with the rejection of an ultimate explanation for the actuality of this world rather than any other. The actual world is no better or worse than any other world.
Thus if there are going to be values, they must lie outside the world. Kant had located these values in a "self in itself," a rational being lying outside the world of appearances in space and time. Although he could not prove, the existence of this self, as it transcends experience, he could at least suppose it, since it does not violate the principle of non-contradiction.
On WittgensteinÆs view, the "metaphysical subject" is nothing rational, for all reasoning concerns the world, and the metaphysical subject is the "limit" of the world. It is like the eye in the visual field, which sees things but does not cast its gaze upon itself. Ethical concerns have to do with nothing in the world, but rather affect the view of the world itself. This view cannot be expressed in language, which is confined to the description of what is in the world. In the end, it is a mystery. WittgensteinÆs apparent attempt to say what cannot be said is futile, and he ended his essay saying that his propositions are like a ladder which can be kicked away when it has gotten us where we want to go.
Eventually Wittgenstein became dissatisfied with his early views, and in the Philosophical Investigations he repudiated them to a large extent. The seeds of the destruction of the Tractatus are found in 4.002.
"Everyday language is a part of the human organism and is no less complicated than it. It is not humanly possible to gather immediately from it what the logic of language is. Language disguises thought. So much so, that from the outward form of the clothing it is impossible to infer the form of the thought beneath it, because the outward form of the clothing is not designed to reveal the form of the body, but for entirely different purposes. The tacit conventions on which the understanding of everyday language depends are enormously complicated."
Here Wittgenstein had carried on in the tradition of Socrates, who wished to find something like the "form of the thought" beneath the utterances of his adversaries. (Note that these forms are not the same in detail for the two.) Finding the form is the Holy Grail of philosophy, promising the solution of all philosophical problems.
But in the later work, Wittgenstein repudiated the project, for reasons that can be seen already in 4.002 of the Tractatus. What he had called the "complication of the conventions on which understanding everyday language depends" is not a mere mask of something simple and pure beneath, but rather is all there is to the matter. The significance of language is the uses to which it is put. In Section 23 of the Investigations, Wittgenstein listed a number of varied uses of language. He concluded, "It is interesting to compare the multiplicity of the tools in language with what logicians have said about the structure of language. (Including the author of the Tractatus Logico-Philosophicus.)" The upshot of the comparison is that the author of the older book was mistaken.
Much of the project of WittgensteinÆs Tractatus was to uncover a logical form of thought, a form which defines what can be said about the world, by revealing the possibilities of the combinations of objects. This project is similar to the Socrates/Plato project which also culminated with forms, though of a quite different sort. What the two projects had in common was the search for something clear and unambiguous standing behind the disorder of ordinary language. Both Plato and Wittgenstein believed they had found the what they were looking for.
But just as Plato ultimately posed severe challenges to his own theory of forms, Wittgenstein abandoned his search. The seeds of his difficulties lay in the Tractatus itself, in the recognition at 4.002 of the web of tacit conventions required for ordinary language to work. That is, we make many unstated, informal agreements about how words are to be used. In the Philosophical Investigations, Wittgenstein found that the dynamics of language rely so much on convention that he abandoned the quest for an underlying logical form altogether. Meaning becomes identified with use.
Each language, rather than having a single underlying logical form, instead is a kind of game, which is played by its speakers according to rules. The rules vary from game to game. A very simple language game, as described in the earliest sections of the Investigation, co-ordinates the speaking of words with certain commands, thus making the activity of commanding an ineliminable part of the game. This activity is not to be captured by the notion of a logical form. Further, it is impossible to tell from the outside which rules are being followed by those playing a game. Any given pattern of behavior is compatible with any number of rules. In a degenerate example, on a TV sit-com, a dog barks twice after being given a choice of three items to eat. The man offering the food takes the dog to be asking for the second of the stated items. Can we say that the dog is not following a rule?
Given all the varieties of language games that might be played, we might look for a common element, a form underlying language games as such. But here Wittgenstein noted that there is no fixed concept of a game itself. Different games (board games, card games, athletic games, for example) have no one thing in common, other than being human activities which are "played" by rules. The resemblance among the games is like that shown among members of a family. So philosophy is frustrated when it seeks a single form for language itself; and such a form is just what was sought by "the author of Tractatus Logico-Philosophicus."
Wittgenstein proposed that the traditional pursuit of philosophy is futile, and that philosophers could profit most from a kind of therapy which would free them from their quest for an underlying logical form that would capture all thought. Philosophers are like flies caught in a bottle, buzzing away, trying to break through the glass. The real task of Wittgenstein's work, as he saw it then, was to show the fly the way out of the bottle.
For many philosophers, this sounded the death-knell of traditional philosophy. Some philosophers continue to proclaim the death of philosophy. One of the most notable is Richard Rorty, who gave up his philosophy professorship at Princeton (the top-rated philosophy department in the United States) to take a job in the University of Virginia. Rorty has spent twenty years trying to show how philosophers have gone wrong in trying to understand the mind as the "mirror of nature." He has a great many followers both in and outside of philosophy.
Nonetheless, the tide has swung back toward the traditional goals of philosophy, toward the attempt to clarify concepts in the manner demanded by Socrates. Part of the return to the tradition has been fueled by new developments in logic. Just as Wittgenstein was stimulated to write much of the Tractatus under the influence of the new logic of his period, contemporary philosophers have responded to new developments in the logic of necessity and possibility, "modal logic."
There has been some departure from the traditional in methodology, however. Most philosophers have given up the Platonic/Cartesian notion of rational intuition, in favor of what might be called linguistic intuition. The analysis of a concept is intended to conform to our most basic thoughts about proper usage of terms.
I suggest, however, that this revival of the notion of intuition is not the final story in philosophical method. There is disagreement, sometimes irresolvable, about intuitions. I believe there is something suspicious about the "basic" character of intuition, because intuitions are shaped by life experiences. A legacy of Wittgenstein is the recognition that "forms of life" must be taken into account in the understanding of linguistic practices. Consider a student who has "ordinary" intuitions about what it is to know, for example. This student will make all kinds of knowledge claims at the drop of a hat. But then expose the student to a diet of Descartes and Hume, and suddenly you have a skeptic on your hands. If you make a knowledge claim, that student will demand an explanation of how you can be sure you are not mistaken. When you reply that you cannot tell, the student replies triumphantly that, obviously, you lack knowledge. (Maybe this recounts the experience of the author of these notes.)