Ludwig Wittgenstein is particularly interesting because in Philosophical Investigations (PI) he repudiated all of his earlier work in logical positivism and the Tractatus Logico-Philosophicus (TLP), along with much of what was traditionally thought of as philosophy, and took a radically new track in the last twenty years of his life. Young Wittgenstein was more certain that he had solved all major philosophical problems, while the older Wittgenstein had completely lost all such certainties. There were even hints in his earlier work of this later, more explicit existential despair, pessimism and even cynicism about the limits of philosophy, which certainly became more profound over the years. He was no longer able to view the world as consisting of facts that were logical representations of objects that really existed or at least had the potential to exist. Thoughts and ideas formed pictures that were models of reality, while everything outside of this was nonsense (TLP, 1922, 1961, p. 2.12). Even at an early age, Wittgenstein thought that most of the theories of philosophy, metaphysics, aesthetics, epistemology and even his own work were nonsensical -- literally senseless -- and could not be proven or even represented (TLP p. 4.003). Over time they might possibly be corrected by logical analysis, although the older Wittgenstein no longer believed this. Wittgenstein could therefore be interpreted as a nihilist who had given up the traditional philosophical quest for truth, meaning or universal principles, and he has often been described in these terms. This was not the case with Gilbert Ryle and his other major disciples in the decades after his death, he asserted that his major contribution had been to separate philosophy from science, as well as metaphysics or meaningless generalizations and speculations that were not firmly grounded in reality.
Wittgenstein openly denounced his earlier work as too dogmatic, and moved away from logic into theories about language games, which culminated in Philosophical Investigations, published posthumously in 1953. He had come to oppose traditional ideas about logic, truth, thought and philosophy as a whole, and he denied that "individual words in language name objects" (PI, 1953, 2009, p. 1). Words had no meaning most of the time except for how they were used in a particular context, and did not refer to exterior objects or internal mental processes. They could be used for a wide variety of purposes and the task of the philosopher was to describe these without making profound generalizations (PI, p. 66). Language games could take an almost infinite number of forms, which made it difficult to define the concept at all, but ranging from telling jokes to acting to engaging in theoretical speculation. Wittgenstein rejected all general explanations in this early form of postmodernism and discourse analysis, but insisted on examining the actual use of words through "a complicated network of similarities, overlapping and crisscrossing" (PI, p. 66).
All language games had rules, and these were socially and historically constructed rather than ideals or absolutes in the Platonic sense. Once again, the main questions were how the rules were learned, enforced, altered or ignored in actual practice. They were also made to be broken so that "if everything can be made out to accord with the rule, then it can also be made out to conflict with it. And so there would be neither accord nor conflict" (PI 201). At times, Wittgenstein seemed to be skeptical that any facts existed at all about how such rules might be used. In addition, all individuals had their own private-language games which were meaningful only to them and followed their own rules. These did not follow the publicly-accepted forms of language and referred only to "what can only be known to the person speaking; to his immediate private sensations" (PI 243). Public languages all had their own grammars, which were not simply rigid rules found in textbooks but described objects and ideas in mutually comprehensible ways. Human life could not exist at all without these shared understandings about grammar in the broadest sense.
In the end, Wittgenstein denied that philosophers should have any real theories or explanations, and regarded philosophy more as a form of therapy. No single, universally valid method or system existed but "there are indeed methods, like different therapies" (PI, p. 133). Philosophy had to be humble and admit that it did not really know the answers to the ultimate questions, and could only offer hints and suggestions to how they might be solved. Most of its previous theories were meaningless verbiage, more language games that could be deconstructed, as postmodernists would use the term. Metaphysical speculations were particularly meaningless and philosophers would do better to say nothing at all than indulge in them. One of Wittgenstein's most important discoveries in Philosophical Investigations was that his work could make "me capable of stopping doing philosophy when I want to" (PI, p. 133).
Although Wittgenstein's writings often seemed obscure and fragmented, as well as notoriously "difficult," his most important disciples like Gilbert Ryle and the analytic philosophers did not regard him as a nihilist at all, but instead praised idea that philosophy was a method rather than a science. Ryle offered one of the clearest and most memorable applications of Wittgenstein's method when he abruptly swept away centuries of metaphysics from Plato to Rene Descartes, who had argued that that all humans had both a body and mind and that the mind was eternal while the body was subject to physical and material laws. Descartes had updated and modernized dualism so that universe was divided between the mind and matter, and the physical world could be explained by mathematical and scientific laws (Ryle, 1949, p. 251). Thomas Hobbes, John Locke and other political and philosophical theorists of the 17th Century were also influenced by the new scientific thought of Galileo, Isaac Newton and William Harvey to one degree, and had to incorporate them into philosophy. Ryle denied that any "ghost in the machine" existed or that the immortal soul somehow operated the physical body (Ryle, p. 252). He admitted that explaining the link between bodies and minds was very difficult, although behaviorists had come to understand that expressions indicate moods and emotions, while vision, hearing and motion are all based on sensory inputs being received by the mind, but no one could actually measure and observe mental processes at the time when Ryle was writing in the 1940s and 1950s. When people are described as knowing, believing, hoping or intending, these verbs certainly refer to internal mental processes and from these philosophers constructed their theories of the mind.
Ryle denied the existence of an eternal soul or mind separate from the body, even though he also conceded that thoughts and emotions could not be described in the language of chemistry and physics alone. Bodies and minds were part of a single whole, just as much as a college or department were all part of a university, even though the mind was a very special organ or machine that was like an internal motor within the body, it could still be understood by physical laws like cause and effect (Ryle, p. 255). Ryle did not regard the mind as purely mechanical device, but as a complex organ that operated on the basis of cause and effect. If the mind was not a ghost or ethereal entity operating a body, it was more a kind of internal-governing motor of the body whose laws of operation were mostly unknown. These laws need not be purely deterministic, however, and Ryle rejected both idealism and materialism because they made an artificial distinction between the mind and body Science cannot prove the existence of God or the immortal soul, and Ryle attacked Descartes for arguing that the mind was a spiritual substance, and instead advocated behaviorism as an explanation for all mental processes (Ryle, p. 257). For Ryle, as well as generations of analytic philosophers, then, Wittgenstein was not a nihilist, but a behaviorist and materialist. His goal was destructive, but not of philosophy as a whole but rather only of those parts that should have been destroyed long ago, knocked down like a house of cards (Biletzi, 2003, p. 99). In dismissing or minimizing the internal world as a private language game that was inaccessible to outsiders, Wittgenstein was focused on the external or public world that was open to empirical observation. He despaired of finding any method for reconciling the objective and subjective language games, and perhaps this could never be done except by denying any distinction between the two (Leung, 2002, p. 5).
Wittgenstein's philosophy may no longer have any pretense towards being a science in its own right, but paradoxically that seems to make it even more compatible with modern science as a whole. If the interpretation of Ryle and the other materialists is correct, then he did regard the mind and brain as being the same, which is certainly compatible with all the present-day research in computer science, neurology and artificial intelligence. Scientific theorists…