Before asking what kind of progress is possible in philosophy, we must first consider if progress is possible at all in philosophy. A common argument against philosophical progress generally goes as follows: philosophy seems to be predominantly armchair-driven, that most of philosophical work is done through arduous pondering. However, it seems as though just sitting on an armchair and thinking cannot possibly reveal new truths, and therefore relying on the armchair method cannot make any progress. Thus, by this reasoning, most philosophy is incapable of progress.

Beyond this straw man argument, two leading opposing grounds against philosophical progress are represented by Ludwig Wittgenstein and Penelope Maddy. Wittgenstein claims that philosophical problems are rooted in conceptual or linguistic confusions. For him, philosophy does not offer any useful revelations about the real world. Maddy’s view is a bit less extreme; she regards those branches of philosophy that are closer to the natural sciences as the only parts of philosophy that can make progress. Both Wittgenstein and Maddy seem to limit philosophy’s capabilities to a certain set of truths, implying that philosophy cannot make much real progress.

Wittgenstein, in his Philosophical Investigations, claims that the problems in philosophy arise from conceptual confusion in language. In particular, he argues against the various ways we might define language from our common usage, called language games, eventually arriving at the conclusion that we cannot adequately and comprehensively outline our system of language and meanings of words. As an analogy, he puts forth that, while mathematics is an academic subject, it is also an activity. So it’s unclear whether the statement ‘two plus two is five’ is incorrect because it is objectively false or because it is an exception to what we do [1]. If this kind of confusion arises from mathematics, a subject known for its certainty and clarity from its established axioms, what happens when there is no universal agreement or a guideline, such as judging whether an expression of feeling is genuine? It seems clear that “if the formation of concepts can be explained by facts of nature, [we] should be interested, not in grammar, but rather in nature which is the basis of grammar” [2]. Since Wittgenstein establishes that we cannot explain the formation of concepts by examining the facts of nature, we are left with the conclusion that explaining the formation of concepts would be better accomplished by exploring the use of concepts in our language rather than some material reference in nature. Thus, for Wittgenstein, the correct methodology and goal of philosophy is to examine and explain the conceptual confusions in our language; philosophy has no access to valuable knowledge of the real world.

To this linguistic argument against philosophical progress, Timothy Williamson responds that philosophers invoking thought and language are no different from other professions using linguistic knowledge. If Smith is on trial for killing Jones, the judge has to discern who is telling the truth. Though the judge establishes veracity through processing largely linguistic information, the case still hinges on the act of murder and punishment [3]. Similarly, when historians evaluate the credibility of a source, they ask “who produced them, when and why?”, but again, historians’ evaluations through invoking knowledge of thought and language doesn’t change the fact that their main point and purpose of inquiry is about history [4]. In the same way, the goal of philosophy should not be confused with one of many methods of achieving that goal. Thus, Wittgenstein’s picture provides a wrong view of philosophical progress.

Less radical than the Wittgenstein picture, Maddy presents the scientist’s argument against philosophy making great progress. She believes that philosophy exists to answer the questions that arise from natural sciences that those subjects cannot answer, and consequently, parts of philosophy unrelated to science are not capable of making progress. In describing the proper methodology for philosophy, Maddy says, “the Second Philosopher conducts her metaphysical inquiry as she does every other inquiry, beginning with observation, experimentation, theory formation and testing, revising and refining as she goes” [5]. In other words, the parts of philosophy that have little to no empirical connections are either not philosophy or useless. Clearly, the picture is driven by empiricism, even bordering on scientism.

Maddy’s criticism of non-empirical evidence and reasoning is not a statement on all forms of non-empirical inquiry; indeed, philosophy of science itself continues to involve significant armchair reasoning. Instead, Maddy’s distinction between parts of philosophy that can and cannot make progress concerns the foundations of the form of philosophical inquiry in question. For her, if a philosophical inquiry finds its base in the sciences, the ensuing philosophical reasoning is capable of making progress despite its reliance on armchair methods. All philosophers end up in the armchair, but Maddy’s second philosopher starts from the lab, whereas other philosophers start from the armchair.

Although Maddy’s belief in science seems reasonable, she is unable to provide a consistent line of argument for evaluating the progress of philosophy. Maddy is highly critical of Descartes’ foundationalism at the start of her Second Philosophy, yet, in her methodology, by regarding empirical observations and scientific beliefs as a privileged form of knowledge, she invokes a belief akin to foundationalism, implying that some beliefs are more reliable than others because they derive from more successful disciplines. Maddy construes this deference to successful science as a judgement made outside of philosophy, but in fact her estimation of a discipline’s success already presupposes philosophical beliefs that stipulate empirical science as the paragon of rational inquiry. The problem here is not exactly that foundationalism is an impossible epistemological strategy, and that therefore Maddy’s privileging of science is likewise implausible. Rather, Maddy herself seems deeply, if implicitly, committed to a form of philosophical judgement about which she is officially quite skeptical. In addition to making this mistake, by trying to categorize an initial set of beliefs and observations, Maddy seems to neglect Quine’s well-known, and highly convincing, demonstration that observational sentences are not easily distinguished from non-empirical sentences. Maddy’s supposedly anti-foundationalist, but largely self-undermining, deference to science, together with the more familiar problems associated with distinguishing observation sentences, cast considerable doubt on her vision of philosophical progress.

Considerations from the history of science, and from scientific methodology, equally undermine Maddy’s bias towards empirical foundations. Despite using empirical justifications, natural sciences such as physics could not have made the progress that they have made without purely non-empirical thought experiments, as evidenced in the works of Galileo and Einstein [6]. These thought experiments in natural sciences were often later confirmed by physical experiments, but the point still remains that these thought experiments began in the armchair, instead of being started in the lab, and confirmation is often a long time in coming. In the same way, philosophy based on non-empirical reasoning can be as useful as philosophy based on empirical observations. Thus, the goal towards which philosophy progresses cannot be limited to solely aiding natural sciences as Maddy suggests.