Philosophical methodology encompasses the methods used to philosophize and the study of these methods. Methods of philosophy are procedures for conducting research, creating new theories, and selecting between competing theories. In addition to the description of methods, philosophical methodology also compares and evaluates them.
Philosophers have employed a great variety of methods. Methodological skepticism tries to find principles that cannot be doubted. The geometrical method deduces theorems from self-evident axioms. The phenomenological method describes first-person experience. Verificationists study the conditions of empirical verification of sentences to determine their meaning. Conceptual analysis decomposes concepts into fundamental constituents. Common-sense philosophers use widely held beliefs as their starting point of inquiry, whereas ordinary language philosophers extract philosophical insights from ordinary language. Intuition-based methods, like thought experiments, rely on non-inferential impressions. The method of reflective equilibrium seeks coherence among beliefs, while the pragmatist method assesses theories by their practical consequences. The transcendental method studies the conditions without which an entity could not exist. Experimental philosophers use empirical methods.
The choice of method can significantly impact how theories are constructed and the arguments used to support them. As a result, methodological disagreements can lead to philosophical disagreements.
Definition
The term "philosophical methodology" refers either to the methods used to philosophize or to the branch of metaphilosophy studying these methods. Philosophical methodology studies the methods of philosophy. It is not primarily concerned with whether a philosophical position, such as metaphysical dualism or utilitarianism, is true or false. Instead, it asks how one can determine which position should be adopted.
In the widest sense, any principle for choosing between competing theories may be considered as part of the methodology of philosophy. In this sense, the philosophical methodology is "the general study of criteria for theory selection". For example, Occam’s Razor is a methodological principle of theory selection favoring simple over complex theories. Because of this, the problem of the methods of philosophy is central to how philosophical claims are to be justified. It is motivated by the search for an absolutely certain foundation of knowledge. The method for finding these foundations is doubt: only that which is indubitable can serve this role. Historically, it can be understood as a response to methodological skepticism: it consists in trying to find a foundation of certain knowledge and then expanding this foundation through deductive inferences. The theorems arrived at this way may be challenged in two ways. On the one hand, they may be derived from axioms that are not as self-evident as their defenders proclaim and thereby fail to inherit the status of absolute certainty. Another example is the causal axiom of Spinoza's system that "the knowledge of an effect depends on and involves knowledge of its cause", which has been criticized in various ways. In this sense, philosophical systems built using the geometrical method are open to criticisms that reject their basic axioms. A different form of objection holds that the inference from the axioms to the theorems may be faulty, for example, because it does not follow a rule of inference or because it includes implicitly assumed premises that are not themselves self-evident. The phenomenological method aims to study the appearances themselves and the relations found between them. This is achieved through the so-called phenomenological reduction, also known as epoché or bracketing: the researcher suspends their judgments about the natural external world in order to focus exclusively on the experience of how things appear to be, independent of whether these appearances are true or false. But phenomenology has been heavily criticized because of this overly optimistic outlook concerning the certainty of its insights. A different objection to the method of phenomenological reduction holds that it involves an artificial stance that gives too much emphasis on the theoretical attitude at the expense of feeling and practical concerns.
Another phenomenological method is called "eidetic variation". It is used to study the essences of things. This is done by imagining an object of the kind under investigation. The features of this object are then varied in order to see whether the resulting object still belongs to the investigated kind. If the object can survive the change of a certain feature then this feature is inessential to this kind. Otherwise, it belongs to the kind's essence. For example, when imagining a triangle, one can vary its features, like the length of its sides or its color. These features are inessential since the changed object is still a triangle, but it ceases to be a triangle if a fourth side is added.
Verificationism
The method of verificationism consists in understanding sentences by analyzing their characteristic conditions of verification, i.e. by determining which empirical observations would prove them to be true. A central motivation behind this method has been to distinguish meaningful from meaningless sentences. This is sometimes expressed through the claim that "[the] meaning of a statement is the method of its verification". Meaningful sentences, like the ones found in the natural sciences, have clear conditions of empirical verification. But since most metaphysical sentences cannot be verified by empirical observations, they are deemed to be non-sensical by verificationists. Verificationism has been criticized on various grounds. On the one hand, it has proved very difficult to give a precise formulation that includes all scientific claims, including the ones about unobservables. This would lead to the implausible conclusion that even for the empirical sciences, many of their claims would be meaningless. But on a deeper level, the basic claim underlying verificationism seems itself to be meaningless by its own standards: it is not clear what empirical observations could verify the claim that the meaning of a sentence is the method of its verification. In this sense, verificationism would be contradictory by directly refuting itself. These and other problems have led some theorists, especially from the sciences, to adopt falsificationism instead. It is a less radical approach that holds that serious theories or hypotheses should at least be falsifiable, i.e. there should be some empirical observations that could prove them wrong.
Conceptual analysis
The goal of conceptual analysis is to decompose or analyze a given concept into its fundamental constituents. It consists in considering a philosophically interesting concept, like knowledge, and determining the necessary and sufficient conditions for whether the application of this concept is true. If it results in an open or intelligible question, then the analysis does not exactly correspond to what we have in mind when we use the term. This can be used, for example, to reject the utilitarian claim that "goodness" is "whatever maximizes happiness". The underlying argument is that the question "Is what is good what maximizes happiness?" is an open question, unlike the question "Is what is good what is good?", which is a closed question. One problem with this approach is that it results in a very strict conception of what constitutes a correct conceptual analysis, leading to the conclusion that many concepts, like "goodness", are simple or indefinable. In this sense, it is closely related to the method of conceptual engineering, which consists in redefining concepts in fruitful ways or developing new interesting concepts. This method has been applied, for example, to the concepts of gender and race. Common sense philosophers use these beliefs as their starting point of philosophizing. This often takes the form of criticism directed against theories whose premises or conclusions are very far removed from how the average person thinks about the issue in question. G. E. Moore, for example, rejects J. M. E. McTaggart's sophisticated argumentation for the unreality of time based on his common-sense impression that time exists. He holds that his simple common-sense impression is much more certain than that McTaggart's arguments are sound, even though Moore was unable to pinpoint where McTaggart's arguments went wrong. According to his method, common sense constitutes an evidence base. For example, Albert Einstein's theory of relativity constitutes a radical departure from the common-sense conception of space and time, and quantum physics poses equally serious problems to how we tend to think about how elementary particles behave. This puts into question that common sense is a reliable source of knowledge. Another problem is that for many issues, there is no one universally accepted common-sense opinion. In such cases, common sense only amounts to the majority opinion, which should not be blindly accepted by researchers. This problem can be approached by articulating a weaker version of the common-sense method.
Ordinary language philosophy
The method of ordinary language philosophy consists in tackling philosophical questions based on how the related terms are used in ordinary language. In this sense, it is related to the method of common sense but focuses more on linguistic aspects.
Intuition and thought experiments
Methods based on intuition, like ethical intuitionism, use intuitions to evaluate whether a philosophical claim is true or false. In this context, intuitions are seen as a non-inferential source of knowledge: they consist in the impression of correctness one has when considering a certain claim. They are intellectual seemings that make it appear to the thinker that the considered proposition is true or false without the need to consider arguments for or against the proposition. This is sometimes expressed by saying that the proposition in question is self-evident. Examples of such propositions include "torturing a sentient being for fun is wrong" or "it is irrational to believe both something and its opposite". This often takes the form of thought experiments, in which certain situations are imagined with the goal of determining the possible consequences of the imagined scenario. These consequences are assessed using intuition and counterfactual thinking. In some cases, the imagined scenario is physically possible but it would not be feasible to make an actual experiment due to the costs, negative consequences, or technological limitations. Some of its defenders claim that intuition is a reliable source of knowledge just like perception, with the difference being that it happens without the sensory organs. Others compare it not to perception but to the cognitive ability to evaluate counterfactual conditionals, which may be understood as the capacity to answer what-if questions. But the reliability of intuitions has been contested by its opponents. For example, wishful thinking may be the reason why it intuitively seems to a person that a proposition is true without providing any epistemological support for this proposition. Another objection, often raised in the empirical and naturalist tradition, is that intuitions do not constitute a reliable source of knowledge since the practitioner restricts themselves to an inquiry from their armchair instead of looking at the world to make empirical observations.
Reflective equilibrium
Reflective equilibrium is a state in which a thinker has the impression that they have considered all the relevant evidence for and against a theory and have made up their mind on this issue. It is a state of coherent balance among one's beliefs. This does not imply that all the evidence has really been considered, but it is tied to the impression that engaging in further inquiry is unlikely to make one change one's mind, i.e. that one has reached a stable equilibrium. In this sense, it is the endpoint of the deliberative process on the issue in question. For example, the narrow method of reflective equilibrium may lead some moral philosophers towards utilitarianism and others towards Kantianism. In this sense, "[t]he test of truth is utility: it's true if it works". Pragmatists approach intractable philosophical disputes in a down-to-earth fashion by asking about the concrete consequences associated, for example, with whether an abstract metaphysical theory is true or false. This is also intended to clarify the underlying issues by spelling out what would follow from them.
Succinct summaries of the pragmatic method base it on the pragmatic maxim, of which various versions exist. An important version is due to Charles Sanders Peirce: "Consider what effects, which might conceivably have practical bearings, we conceive the object of our conception to have. Then, our conception of those effects is the whole of our conception of the object." Various criticisms to the pragmatic method have been raised. For example, it is commonly rejected that the terms "true" and "useful" mean the same thing. A closely related problem is that believing in a certain theory may be useful to one person and useless to another, which would mean the same theory is both true and false.
Transcendental method
The transcendental method () is used to study phenomena by reflecting on the conditions of possibility of these phenomena. For example, it has been used to argue for the existence of an external world based on the premise that the experience of the temporal order of our mental states would not be possible otherwise.
Transcendental arguments have faced various challenges. On the one hand, the claim that the belief in a certain assumption is necessary for the experience of a certain entity is often not obvious. So in the example above, critics can argue against the transcendental argument by denying the claim that an external world is necessary for the experience of the temporal order of our mental states. But even if this point is granted, it does not guarantee that the assumption itself is true. So even if the belief in a given proposition is a psychological necessity for a certain experience, it does not automatically follow that this belief itself is true. Instead, it could be the case that humans are just wired in such a way that they have to believe in certain false assumptions.
Experimental philosophy
Experimental philosophy is the most recent development of the methods discussed in this article: it began only in the early years of the 21st century. This usually takes the form of surveys probing the intuitions of ordinary people and then drawing conclusions from the findings. For example, one such inquiry came to the conclusion that justified true belief may be sufficient for knowledge despite various Gettier cases claiming to show otherwise. and "[i]t was their wonder, astonishment, that first led men to philosophize and still leads them". This position is also adopted in the more recent philosophy of Nicolai Hartmann. Various other types of methods were discussed in ancient Greek philosophy, like analysis, synthesis, dialectics, demonstration, definition, and reduction to absurdity. The medieval philosopher Thomas Aquinas identifies composition and division as ways of forming propositions while he sees invention and judgment as forms of reasoning from the known to the unknown. One such method is based on the idea that, everything else being equal, the simpler theory is to be preferred. Another gives preference to the theory that provides the best explanation. According to the method of epistemic conservatism, we should, all other things being equal, prefer the theory which, among its competitors, is the most conservative, i.e. the one closest to the beliefs we currently hold.
According to truthmaker theorists, every true proposition is true because another entity, its truthmaker, exists. This principle can be used as a methodology to critically evaluate philosophical theories.
In philosophy, the term "genealogical method" refers to a form of criticism that tries to expose commonly held beliefs by uncovering their historical origin and function.
Disagreements and influence
The disagreements within philosophy do not only concern which first-order philosophical claims are true, they also concern the second-order issue of which philosophical methods to use. Seeing philosophy as an empirical science brings its methods much closer to the methods found in the natural sciences. Seeing it as the attempt to clarify concepts and increase understanding, on the other hand, usually leads to a methodology much more focused on apriori reasoning. But some philosophers reject its importance by emphasizing that "preoccupation with questions about methods tends to distract us from prosecuting the methods themselves".
Relation to other fields
Science
The methods of philosophy differ in various respects from the methods found in the natural sciences. One important difference is that philosophy does not use experimental data obtained through measuring equipment like telescopes or cloud chambers to justify its claims. Experimental philosophers are an important exception: they use methods found in social psychology and other empirical sciences to test their claims. Another difference between scientific and philosophical methodology is that there is wide agreement among scientists concerning their methods, testing procedures, and results. This is often linked to the fact that science has seen much more progress than philosophy. These principles can then be used as premises to support further conclusions. Some approaches to philosophical methodology emphasize that these arguments have to be deductively valid, i.e. that the truth of their premises ensures the truth of their conclusion. In other cases, philosophers may commit themselves to working hypotheses or norms of investigation even though they lack sufficient evidence. Such assumptions can be quite fruitful in simplifying the possibilities the philosopher needs to consider and by guiding them to ask interesting questions. But the lack of evidence makes this type of enterprise vulnerable to criticism.