Has philosophy run its course? Does it have a significant role to play in the future development of knowledge? All the sciences we have today may have their origin in philosophical speculation, but this is no argument for the value of philosophy today, in light of the advancement of such sciences. Mathematics can create its own definitions and axioms to proceed with deductive rigor to more complex propositions. Natural science can take for granted the stability of nature, and hence use it as a benchmark to develop and test its theories. While these methods may have their problems, in general there is no arguing that these sciences (and others derived from them) appear to have developed far more in modernity than their father, philosophy, has. Perhaps this development constitutes successful patricide.
Further, it does not seem as though philosophy has triangulated on a more ‘absolutely certain’ metaphysics over time, the way scientific theories appear to have done. The method by which philosophy can decide between systems of ontology is far more complicated and vague than the method science can use to decide between theories. In some sense the debates today are the same as they were in the time of the ancients, over whether the nature of reality is all physical, mental, some combination, or what those terms even mean when employed to describe the world. A materialist and idealist would start with different definitions of the mind, for instance, and continue to develop theories that, rather than being mutually contradictory, are simply meaningless with respect to each other. This is because each side is employing concepts that the other considers nonsense. Hence the similar confusion of how to answer questions of free will, personal identity, or why there is something rather than nothing. This naturally begs the question, if modern physics or biology, with the help of refined mathematical tools, can explore the nature of the universe and its life in a more rigorous, testable way than metaphysics can, then isn’t it reasonable to think of philosophy as an outdated science? If its questions cannot even be answered, is it a science at all?
The first important thing to realize about metaphysical investigation is that there is no method of proceeding that cannot be subject to doubt. There will always be something for a skeptic to pick apart. This is not just a problem with philosophy either. If absolute truth is your concern, then all areas of knowledge can be doubted. The key difference for philosophy consists in the way it sometimes sets its own standards. The natural sciences do not intend such propositions; in fact it is of key importance that scientific propositions be falsifiable. Logic and mathematics alone can be certain of a kind of truth, but this truth only appears through tautology and deduction. It appears to me that any attempt to formulate an absolutely true proposition, in the sense of having the certainty of logic or mathematics along with the relationship to the world of science, is doomed to failure, as it can always be subject to doubt. Any philosophy that claims to have achieved this should be rightly viewed with skepticism. You can’t have your cake and eat it too. Yet this is not a dismissal of the content of metaphysics; rather, it is a critique of its expectations, its stringent requirements for knowledge of the truth. Nor is it a gateway to relativism, so long as we can appeal to grounds for truth other than absolute deductive or intuitive certainty combined with a necessary relationship to the world.
What would these grounds be? Whatever is given. Whatever the facts of our experience are. For example, I notice it is a fact that I feel the pressure of what seems to be a keyboard on what seems to be my fingers. This seeming is important, it is a starting point. I am now in a position to ask: what are the conditions of this seeming? There are some things in my experience that seem to always be there. What could be the conditions of those things? What is the effect of my own awareness or inquiry into these facts of experience? Is that ‘I’? Does it distort my inquiry somehow, or is it the very condition of everything I see? These sorts of questions necessarily leave behind the realm of deductive certainty. For deduction proceeds from solid axioms, and we are not starting with anything solid, but with the natural confusion of our experience. What is given could be dependent on all kinds of things we don’t yet know or haven’t justified. Viewed in this way, propositions like ‘I exist’, or ‘the world exists’ are not indubitable starting points - they are rather arrived at by means of uncertain interpretations of facts, through free speculation on given kinds of experiences.
This always runs the risk of being meaningless sophistry, and rightly so. But if we think about the nature of the inquiry, this risk should not come as a surprise. What metaphysical investigation is aimed at is uncovering or laying out the most general description possible of the world. In this sense there is a natural parallel to theories of everything in theoretical physics, which aim at a similarly general picture of the physical world, in that they aim to explain or unify all the objects of their science under certain simple laws. Metaphysics often engages in similar activity. The categories of Aristotle or Kant are a good example of this. However different their metaphysical systems may be, their categories aim to provide a complete set of the most general kinds of things we experience: substances, qualities, relations, etc. These categories may interpret the facts of our experience differently (e.g. for Aristotle they are simply descriptions of all the different kinds of things, for Kant they are necessary conditions of our experience, not describing the things themselves), but they are both attempts at grounding our experience under a complete and general description.
In physics, these general categories are filled in and made more precise; swap substance for particles, quality for kinds of particles, relation for forces, and add equations that can describe the behavior of these parts of the world in a way that can be tested by experiment. Yet here physics leaves out something that metaphysics should keep; it closes off certain areas of experience that are still open to question. Are these concepts of particles and forces really the most fundamental descriptions of our experience of the world? What about the effect of my mind? What about a description that focuses on the way things appear to me in everyday experience, rather than a highly theoretical and unobservable account? Is a table merely just a collection of particles and forces, or is there a more general description which can incorporate that account, as well as the other facets of my experience in using it, working with it, seeing it? Physics can achieve its rigor, clarity, and simplicity through ignoring these questions, and working out the details of its own specific content.
This closing-off is of course necessary; it is what allows for the rigor and success we see the sciences enjoy. But it comes at the cost of a kind of reflection and patience that philosophy should have. We can see this cost-benefit dynamic play out in almost every field, even within a field. In economics, for example, whole systems are created based on the premise that humans will act rationally in a market environment. These systems may be highly useful, but when taken to the extreme, are given an unwarranted absoluteness when foundational reflection reveals other principles of human behavior at work. One function of philosophy is to create concepts that can govern this kind of scientific organization; to generate new ways of thinking about old things, and arbitrate between what concepts are best suited for particular domains.
This is also why I criticized the standards of knowledge sometimes set by philosophers who want to have metaphysics with the standards of science or mathematics. Philosophy should not close itself in the same way as these disciplines do. Its role is not to supply the absolute bedrock of certainty upon which all other sciences are derived. Rather, its role is the free-form speculating, concept-generating movement at the boundaries of what is thinkable or meaningful. Seen in this way, all the systems of philosophy generated by the great philosophers are indeed a kind of positive development. They are an elaboration and reinterpretation of different systems of concepts that disclose new ways of seeing the general picture of the world.
The activity of philosophy now seems more like the arts instead of the sciences. Consider the ‘development’ of painting; there is no simple progress in the sense that impressionism has displaced realism as the best way to depict the world. Rather, each new way provides a new set of concepts, or techniques, of depicting the world, within which one can develop and perfect the science of impressionism or realism. And this doesn’t mean every style is equally valid either; there are arguments to be made of the relative superiority of certain styles for certain representations. For instance, realism is best for seeing static things in all their detail, whereas impressionism is better at depicting the dynamism of the world, the interplay of light and movement. It is fair to see both as capturing true elements of our experience. We need this kind of artful thinking in philosophy too, lest we become so engaged in the success and apparent clarity of a particular domain of knowledge that we blind ourselves to other possibilities.
Hence philosophy must make its own criteria, its own rules for interpretation and explanation. This does not mean that anything goes; by all means metaphysics should be guided by reason and experience, just as art should be guided by certain conceptions of what constitutes a worthwhile kind of depiction. But these methods are mere guides for creation, and risks need to be taken in order to break new ground. Likewise philosophy needs to take risks with making sense, and in the process perhaps barely say anything meaningful at all, but so long as it continues to try in earnest, with sincerity, its utility will quietly demonstrate itself. It is very possible that great metaphysical systems affect our thinking much more than is noticed. Einstein provides one instance of recognizing this latent utility of philosophy when developing relativity. In a letter to Schlick, 1915:
"...You have also correctly seen that this trend of thought was of great influence on my efforts, and specifically E. Mach and still much more Hume, whose treatise on understanding I studied with fervor and admiration shortly before the discovery of the theory of relativity. It is very well possible that without these philosophical studies I would not have arrived at the solution."
A new system of philosophy can disclose a new way of seeing the world through concepts, the same way a new style of art can do so through visual style. So let's see how the original criticisms of philosophy stand under this new picture. The charge of overall vagueness comes from a misunderstanding of what the goals and methods of philosophy should be. So long as it is a method of achieving absolute certainty, it will always be too vague, since there is no clear method of establishing truth to the same degree and kind as in mathematics, or even science. Hence opposing systems of metaphysics will remain undecidable. From this undecidability comes the charge of lack of development as well, and the frustration of being unable to answer age-old questions. This also relates to the charges of philosophy’s lack of utility and tangible impact on society, explained as a consequence of this lack of development.
My reframing of the activity of philosophy as more of an art than a science should have cleared up these misunderstandings. I have tried to establish that metaphysics must always run the risk of being nonsense in order to be useful, in order to be the speculative counterweight to the success of established concepts. Its very vagueness, then, is actually what constitutes its utility! It is a natural byproduct of the freedom necessary to explore the edges of our thought. The development of metaphysics thus consists in the variety and network of different concepts and methods, all building upon and around each other to disclose different aspects of the world. This is its quiet utility.