I consider myself to be an intellectual conservative, and I think that being an intellectual conservative is a good quality for a philosopher to have. But before I can defend intellectual conservatism I must first explain what I mean by the term. I certainly don’t mean political conservatism. Nor do I mean supporting the positions of respected past philosophers and rejecting opposing views. By intellectual conservatism I mean an approach to problems in which they are addressed without building up an elaborate metaphysical framework and in which the ordinary meaning of words is respected.
Of course I am not in opposition to metaphysics. The nature of properties, causation, and the ultimate nature of reality all fall under the heading of metaphysics, and are issues of interest to me. So when I say that I am in opposition to elaborate metaphysical frameworks I am using metaphysics in the colloquial, and pejorative, usage, to designate something that exists over and above the physical world. The history of philosophy is full of such metaphysical explanations. To explain knowledge, among other things, Plato invoked the non-physical forms. To explain reference Frege invoked the non-physical sense. To explain consciousness Descartes invoked the non-physical mind. Such systems all have their intuitive appeal, and philosophers who are in favor of them have gone into great detail elaborating on them and resolving various internal contradictions. But they are all bad explanations. First of all it seems certain that the physical world is causally closed, and so it is different to see how forms, senses, and souls can fit into it and play the role the theory says that they do. Certainly these things should at least have an influence on our behavior, but our behavior is a physical phenomenon, and thus no such metaphysical entities may be properly said to have a causal influence on it. And even if that wasn’t a problem, even if we weren’t theoretically committed to saying that they play a causal role, it is hard to see how we could have knowledge about them. Knowledge requires an objective basis, in order to provide confidence in its reliability. However, if these metaphysical entities can be known at all it must be though some faculty of intellectual “perception”. But such knowledge would be essentially subjective; even if many people reported the same intellectual perceptions there would be no way for them to verify the intellectual perceptions of each other, to ensure that they are perceiving the same thing. And more importantly there is no way for them to detect any systematic error in such intellectual perception, since there is no way to check it except through further intellectual perception. And even if that weren’t a problem it is hard to see what explanatory value such metaphysical systems could possibly have. Certainly someone who is convinced that such a metaphysical system is true will think that they understand more through it; surely since the system is so complicated it must be telling them something. However, because of causal closure, and the generally descriptive nature of such systems, it does not give them the resources to make more or better predictions about the world. The only thing it does allow them to make claims about is the status of the various metaphysical entities involved in the system. But it is hard to see the value of such knowledge, as it never actually says anything definite about the world outside of this metaphysical system.
Now we do want to talk about some of the same basic things as these metaphysical theories. For example, we might want to speak in abstract terms about whatever it happens to be that makes a word refer to what it does. And we might want to call this thing the sense, in a nod to Frege. But there is no need to remove this sense from the world, as Frege did. We can simply consider it an abstraction or description of mental states. Thus when we use words you and I may share the same sense, but because abstractions and descriptions may fit more than one physical event, just as we may both have shirts that are green without them literally sharing something in common, and not because our minds reach out to the same non-physical entity. And of course abstractions and descriptions suffer from none of the problems that faced the metaphysical systems which I claim that we should reject. Since they apply to particular physical events there is no problem with fitting them into the causal order, nor with coming to have knowledge of them just like we come to have knowledge of anything else, through experiences that are confirmable and repeatable by others. And by fitting into the causal order they can also be good explanations, by, at the very least, being part of good causal explanations.
As I mentioned above the other aspect of the intellectual conservatism I endorse is respecting the ordinary meanings of words. Of course there is a practical aspect to this recommendation, if you don’t mean by the use of a word what people expect you to mean by it then you will be misunderstood, and that is a nuisance. But even in a philosophical investigation of something like causation I think that it is important to define the term in a way that shares some common ground with our ordinary understanding of the word. Of course our ordinary understanding may be deeply flawed, contradictory, or simply superficial. And so obviously I don’t think philosophy should be a slave to our conceptual intuitions. However, often a word has acquired its ordinary meaning because the concepts expressed by it are useful. Consider causation. Causation is philosophically interesting because it is supposed to connect events at different times, govern how things change, and serve as a useful conceptual tool with which we can explain and predict events. Now if we develop a philosophical understanding of causation that is similar to the most part to our intuitive understanding then we can have some confidence that our philosophical understanding of causation shares some of these features, hopefully the ones about it being a good conceptual tool with which to explain and predict things. But if we radically re-define causation in our philosophical investigations then the thing we have a theory about may have none of these properties. It may not be good at explaining or illuminating how events progress over time. So while the concept we have come to an understanding of may be coherent it may not be philosophically interesting like our ordinary concept of causation was. And in that case what purpose does the investigation serve?