In philosophy, a theory of everything (ToE) is an ultimate, all-encompassing explanation or description of nature or reality. [1] [2] [3] Adopting the term from physics, where the search for a theory of everything is ongoing, philosophers have discussed the viability of the concept and analyzed its properties and implications. [1] [2] [3] Among the questions to be addressed by a philosophical theory of everything are: "Why is reality understandable?" – "Why are the laws of nature as they are?" – "Why is there anything at all?" [1]
A philosophical theory of everything, would need to, as much as is possible or makes sense, unify analytic and continental philosophy. Questions such as "Why is there anything at all?" are arguably metaphysics questions and not so much related to a philosophical ToE.
The "system building" style of metaphysics attempts to answer all the important questions in a coherent way, providing a complete picture of the world. The philosophies of Plato and Aristotle could be said to be early examples of comprehensive systems. In the early modern period (17th and 18th centuries), the system-building scope of philosophy is often linked to the rationalist method of philosophy, that is the technique of deducing the nature of the world by pure a priori reason. Examples from the early modern period include Leibniz's monadology, Descartes's dualism, and Spinoza's monism. Hegel's absolute idealism and Whitehead's process philosophy were later systems. At present, work is underway on the structural-systematic philosophy (SSP), to which the following books are devoted: Lorenz B. Puntel, Structure and Being (2008; translation of Struktur und Sein , 2006) and Being and God (2011; translation of Sein und Gott , 2010) and Alan White, Toward a Philosophical Theory of Everything (2014). The SSP makes no claims to finality; it aims to be the best systematic philosophy currently available.
Other philosophers do not believe philosophy should aim so high. Some scientists think a more mathematical approach than philosophy is needed for a ToE, for instance Stephen Hawking wrote in A Brief History of Time that even if we had a ToE, it would necessarily be a set of equations. He wrote, "What is it that breathes fire into the equations and makes a universe for them to describe?" [4]
In "The Price of an Ultimate Theory", [2] originally published in 2000, Nicholas Rescher specifies what he sees as the principal properties of a Theory of Everything and describes an apparent impasse on the road to such a theory.
First, he takes as a presupposition the principle of sufficient reason, which in his formulation states that every fact t has an explanation t':
where E predicates explanation, so that t' E t denotes "t' explains t".
Next, he asserts that the most direct and natural construction of a Theory of Everything T* would confer upon it two crucial features: comprehensiveness and finality. Comprehensiveness says that wherever there is a fact t, T* affords its explanation:
Finality says that as an "ultimate theory", T* has no deeper explanation:
so that the only conceivable explanation of T* is T* itself.
Rescher notes that it is obviously problematic to deploy a theory for its own explanation; at the heart of the traditional conception of explanatory adequacy, he says, is a principle of noncircularity stating that no fact can explain itself:
The impasse is then that the two critical aspects of a Theory of Everything, comprehensiveness and finality, conflict with the fundamental principle of noncircularity. A comprehensive theory which explains everything must explain itself, and a final theory which has no deeper explanation must, by the principle of sufficient reason, have some explanation; consequently it too must be self-explanatory. Rescher concludes that any Theorist of Everything committed to comprehensiveness and finality is bound to regard noncircularity as "something that has to be jettisoned". But how, he asks, can a theory adequately substantiate itself?
Rescher's proposal in "The Price of an Ultimate Theory" is to dualize the concept of explanation so that a fact can be explained either derivationally, by the premises which lead to it, or systemically, by the consequences which follow from it. With derivational explanation, a fact t is explained when it is subsumed by some prior, more fundamental fact t'. With systemic explanation, t is explained when it is a "best fit" for its consequences, where fitness is measured by uniformity, simplicity, connectedness, and other criteria conducive to systemic integration. Rescher concludes that while a theory of everything cannot be explained derivationally (since no deeper explanation can subsume it), it can be explained systemically by its capacity to integrate its consequences.
In his 1996 book The Conscious Mind, [5] David Chalmers argues that a theory of everything must explain consciousness, that consciousness does not logically supervene on the physical, and that therefore a fundamental theory in physics would not be a theory of everything. A truly final theory, he argues, needs not just physical properties and laws, but phenomenal or protophenomenal properties and psychophysical laws explaining the relationship between physical processes and conscious experience. He concludes that "[o]nce we have a fundamental theory of consciousness to accompany a fundamental theory in physics, we may truly have a theory of everything." Developing such a theory will not be straightforward, he says, but "it ought to be possible in principle."
In "Prolegomena to Any Future Philosophy", [3] a 2002 essay in the Journal of Evolution and Technology , Mark Alan Walker discusses modern responses to the question of how to reconcile "the apparent finitude of humans" with what he calls "the traditional telos of philosophy—the attempt to unite thought and Being, to arrive at absolute knowledge, at a final theory of everything." He contrasts two ways of closing this "gap between the ambitions of philosophy, and the abilities of human philosophers": a "deflationary" approach in which philosophy is "scaled down into something more human" and the attempt to achieve a theory of everything is abandoned, and an "inflationary", transhumanist approach in which philosophers are "scaled up" by advanced technology into "super-intelligent beings" better able to pursue such a theory.
In "Holistic Explanation and the Idea of a Grand Unified Theory", [1] originally presented as a lecture in 1998, Rescher identifies two negative reactions to the idea of a unified, overarching theory: reductionism and rejectionism. Reductionism holds that large-scale philosophical issues can be meaningfully addressed only when divided into lesser components, while rejectionism holds that questions about such issues are illegitimate and unanswerable. Against reductionism, Rescher argues that explaining individual parts does not explain the coordinating structure of the whole, so that a collectivized approach is required. Against rejectionism, he argues that the question of the "reason" – the "why" – behind existence is pressing, important, and not obviously meaningless.
In the philosophy of religion, a cosmological argument is an argument for the existence of God based upon observational and factual statements concerning the universe typically in the context of causation, change, contingency or finitude. In referring to reason and observation alone for its premises, and precluding revelation, this category of argument falls within the domain of natural theology. A cosmological argument can also sometimes be referred to as an argument from universal causation, an argument from first cause, the causal argument or the prime mover argument.
Existence is the state of having being or reality in contrast to nonexistence and nonbeing. Existence is often contrasted with essence: the essence of an entity is its essential features or qualities, which can be understood even if one does not know whether the entity exists.
Metaphilosophy, sometimes called the philosophy of philosophy, is "the investigation of the nature of philosophy". Its subject matter includes the aims of philosophy, the boundaries of philosophy, and its methods. Thus, while philosophy characteristically inquires into the nature of being, the reality of objects, the possibility of knowledge, the nature of truth, and so on, metaphilosophy is the self-reflective inquiry into the nature, aims, and methods of the activity that makes these kinds of inquiries, by asking what is philosophy itself, what sorts of questions it should ask, how it might pose and answer them, and what it can achieve in doing so. It is considered by some to be a subject prior and preparatory to philosophy, while others see it as inherently a part of philosophy, or automatically a part of philosophy while others adopt some combination of these views.
Process philosophy, also ontology of becoming, or processism, is an approach in philosophy that identifies processes, changes, or shifting relationships as the only real experience of everyday living. In opposition to the classical view of change as illusory or accidental, process philosophy posits transient occasions of change or becoming as the only fundamental things of the ordinary everyday real world.
Dialectic, also known as the dialectical method, refers originally to dialogue between people holding different points of view about a subject but wishing to arrive at the truth through reasoned argumentation. Dialectic resembles debate, but the concept excludes subjective elements such as emotional appeal and rhetoric. It has its origins in ancient philosophy and continued to be developed in the Middle Ages.
Pragmatism is a philosophical tradition that views language and thought as tools for prediction, problem solving, and action, rather than describing, representing, or mirroring reality. Pragmatists contend that most philosophical topics—such as the nature of knowledge, language, concepts, meaning, belief, and science—are best viewed in terms of their practical uses and successes.
Mereology is the philosophical study of part-whole relationships, also called parthood relationships. As a branch of metaphysics, mereology examines the connections between parts and their wholes, exploring how components interact within a system. This theory has roots in ancient philosophy, with significant contributions from Plato, Aristotle, and later, medieval and Renaissance thinkers like Thomas Aquinas and John Duns Scotus. Mereology gained formal recognition in the 20th century through the pioneering works of Polish logician Stanisław Leśniewski, who introduced it as part of a comprehensive framework for logic and mathematics, and coined the word "mereology". The field has since evolved to encompass a variety of applications in ontology, natural language semantics, and the cognitive sciences, influencing our understanding of structures ranging from linguistic constructs to biological systems.
Nicholas Rescher was a German-born American philosopher, polymath, and author, who was a professor of philosophy at the University of Pittsburgh from 1961. He was chairman of the Center for Philosophy of Science and chairman of the philosophy department.
In the philosophy of mind, panpsychism is the view that the mind or a mind-like aspect is a fundamental and ubiquitous feature of reality. It is also described as a theory that "the mind is a fundamental feature of the world which exists throughout the universe". It is one of the oldest philosophical theories, and has been ascribed in some form to philosophers including Thales, Plato, Spinoza, Leibniz, Schopenhauer, William James, Alfred North Whitehead, and Bertrand Russell. In the 19th century, panpsychism was the default philosophy of mind in Western thought, but it saw a decline in the mid-20th century with the rise of logical positivism. Recent interest in the hard problem of consciousness, and developments in the fields of neuroscience, psychology, and quantum mechanics have revived interest in panpsychism in the 21st century.
In philosophy and science, a first principle is a basic proposition or assumption that cannot be deduced from any other proposition or assumption. First principles in philosophy are from first cause attitudes and taught by Aristotelians, and nuanced versions of first principles are referred to as postulates by Kantians.
In contemporary philosophy, a brute fact is a fact that cannot be explained in terms of a deeper, more "fundamental" fact. There are two main ways to explain something: say what "brought it about", or describe it at a more "fundamental" level. For example, a cat displayed on a computer screen can be explained, more "fundamentally", in terms of certain voltages in bits of metal in the screen, which in turn can be explained, more "fundamentally", in terms of certain subatomic particles moving in a certain manner. If one were to keep explaining the world in this way and reach a point at which no more "deeper" explanations can be given, then one would have found some facts which are brute or inexplicable, in the sense that we cannot give them an ontological explanation. As it might be put, there may exist some things that just are.
Bastiaan Cornelis van Fraassen is a Dutch-American philosopher noted for his contributions to philosophy of science, epistemology and formal logic. He is a Distinguished Professor of Philosophy at San Francisco State University and the McCosh Professor of Philosophy Emeritus at Princeton University.
A free logic is a logic with fewer existential presuppositions than classical logic. Free logics may allow for terms that do not denote any object. Free logics may also allow models that have an empty domain. A free logic with the latter property is an inclusive logic.
The four causes or four explanations are, in Aristotelian thought, four fundamental types of answer to the question "why?" in analysis of change or movement in nature: the material, the formal, the efficient, and the final. Aristotle wrote that "we do not have knowledge of a thing until we have grasped its why, that is to say, its cause." While there are cases in which classifying a "cause" is difficult, or in which "causes" might merge, Aristotle held that his four "causes" provided an analytical scheme of general applicability.
Everything, every-thing, or every thing, is all that exists; it is an antithesis of nothing, or its complement. It is the totality of things relevant to some subject matter. Without expressed or implied limits, it may refer to anything. The universe is everything that exists theoretically, though a multiverse may exist according to theoretical cosmology predictions. It may refer to an anthropocentric worldview, or the sum of human experience, history, and the human condition in general. Every object and entity is a part of everything, including all physical bodies and in some cases all abstract objects.
The Conscious Mind: In Search of a Fundamental Theory was published in 1996, and is the first book written by David Chalmers, an Australian philosopher specialising in philosophy of mind. Although the book has been greatly influential, Chalmers maintains that it is "far from perfect", as most of it was written as part of his PhD dissertation after "studying philosophy for only four years".
Interactionism or interactionist dualism is the theory in the philosophy of mind which holds that matter and mind are two distinct and independent substances that exert causal effects on one another. An example of your mind influencing your body would be if you are depressed, you can observe the effects on your body, such as a slouched posture, a lackluster smile, etc. Another example, this time of your body affecting your mind would be: If you struck your toe very forcefully on a door, you would experience terrible pain. Interactionism is one type of dualism, traditionally a type of substance dualism though more recently also sometimes a form of property dualism. Many philosophers and scientists have responded to this theory with arguments both supporting and opposing its relevance to life and whether the theory corresponds to reality.
"Why is there anything at all?" or "Why is there something rather than nothing?" is a question about the reason for basic existence which has been raised or commented on by a range of philosophers and physicists, including Gottfried Wilhelm Leibniz, Ludwig Wittgenstein, and Martin Heidegger, who called it "the fundamental question of metaphysics".
Is There a God? is a 1996 book by British philosopher of religion Richard Swinburne, claiming the existence of the Abrahamic God. The argument rests on an updated version of natural theology with biological evolution and Big Bang theory using scientific inference. In 2010, a revised version of the original book was released under the same title.
Definitions of philosophy aim at determining what all forms of philosophy have in common and how to distinguish philosophy from other disciplines. Many different definitions have been proposed but there is very little agreement on which is the right one. Some general characteristics of philosophy are widely accepted, for example, that it is a form of rational inquiry that is systematic, critical, and tends to reflect on its own methods. But such characteristics are usually too vague to give a proper definition of philosophy. Many of the more concrete definitions are very controversial, often because they are revisionary in that they deny the label philosophy to various subdisciplines for which it is normally used. Such definitions are usually only accepted by philosophers belonging to a specific philosophical movement. One reason for these difficulties is that the meaning of the term "philosophy" has changed throughout history: it used to include the sciences as its subdisciplines, which are seen as distinct disciplines in the modern discourse. But even in its contemporary usage, it is still a wide term spanning over many different subfields.