philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...

, a theory of everything (ToE) is an ultimate, all-encompassing explanation or description of

nature Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...

reality Reality is the sum or aggregate of all that is real or existent within a system, as opposed to that which is only imaginary. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, r ...

.Rescher, Nicholas (2006a). "Holistic Explanation and the Idea of a Grand Unified Theory". ''Collected Papers IX: Studies in Metaphilosophy''.Rescher, Nicholas (2006b). "The Price of an Ultimate Theory". ''Collected Papers IX: Studies in Metaphilosophy''.
Googlebooks preview
Walker, Mark Alan (March 2002).

''Journal of Evolution and Technology'' Vol. 10. Adopting the term from physics, where the search for a

theory of everything A theory of everything (TOE or TOE/ToE), final theory, ultimate theory, unified field theory or master theory is a hypothetical, singular, all-encompassing, coherent theoretical framework of physics that fully explains and links together all asp ...

is ongoing, philosophers have discussed the viability of the concept and analyzed its properties and implications. 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?"

Comprehensive philosophical systems

The "system building" style of

metaphysics Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...

attempts to answer ''all'' the important questions in a coherent way, providing a complete picture of the world. The philosophies of

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

and

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...

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 ("from the earlier") and ("from the later") are Latin phrases used in philosophy to distinguish types of knowledge, justification, or argument by their reliance on empirical evidence or experience. knowledge is independent from current ex ...

'' reason. Examples from the early modern period include

Leibniz Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of mathema ...

monadology The ''Monadology'' (french: La Monadologie, 1714) is one of Gottfried Leibniz's best known works of his later philosophy. It is a short text which presents, in some 90 paragraphs, a metaphysics of simple substances, or '' monads''. Text Dur ...

, Descartes's dualism, and

Spinoza Baruch (de) Spinoza (born Bento de Espinosa; later as an author and a correspondent ''Benedictus de Spinoza'', anglicized to ''Benedict de Spinoza''; 24 November 1632 – 21 February 1677) was a Dutch philosopher of Portuguese-Jewish origin, b ...

monism Monism attributes oneness or singleness (Greek: μόνος) to a concept e.g., existence. Various kinds of monism can be distinguished: * Priority monism states that all existing things go back to a source that is distinct from them; e.g., i ...

Hegel Georg Wilhelm Friedrich Hegel (; ; 27 August 1770 – 14 November 1831) was a German philosopher. He is one of the most important figures in German idealism and one of the founding figures of modern Western philosophy. His influence extends a ...

absolute idealism Absolute idealism is an ontologically monistic philosophy chiefly associated with G. W. F. Hegel and Friedrich Schelling, both of whom were German idealist philosophers in the 19th century. The label has also been attached to others such as Josi ...

and Whitehead's

process philosophy Process philosophy, also ontology of becoming, or processism, is an approach to philosophy that identifies processes, changes, or shifting relationships as the only true elements of the ordinary, everyday real world. In opposition to the classic ...

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 ''A Brief History of Time: From the Big Bang to Black Holes'' is a book on theoretical cosmology by English physicist Stephen Hawking. It was first published in 1988. Hawking wrote the book for readers who had no prior knowledge of physics. I ...

'' 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?"

Nicholas Rescher

Properties and impasse of self-substantiation

In "The Price of an Ultimate Theory", originally published in 2000,

Nicholas Rescher Nicholas Rescher (; ; born 15 July 1928) is a German-American philosopher, polymath, and author, who has been a professor of philosophy at the University of Pittsburgh since 1961. He is chairman of the Center for Philosophy of Science and was for ...

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.

Properties

Principle of sufficient reason

First, he takes as a presupposition the

principle of sufficient reason The principle of sufficient reason states that everything must have a reason or a cause. The principle was articulated and made prominent by Gottfried Wilhelm Leibniz, with many antecedents, and was further used and developed by Arthur Schopenhau ...

, which in his formulation states that every fact ''t'' has an explanation ''t: :

\forall t \, \exists t' \, (t'\ E\ t)

where E predicates explanation, so that ''t''' E ''t'' denotes "''t explains ''t''".

Comprehensiveness

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: :

\forall t \, (T^*\ E\ t)

Finality

Finality says that as an "ultimate theory", ''T*'' has no deeper explanation: :

\forall t \, ((t\ E\ T^*) \to (t = T^*))

so that the only conceivable explanation of ''T*'' is ''T*'' itself.

Noncircularity

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: :

\nexists t \, (t\ E\ t)

Impasse

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?

Ways forward

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'',

David Chalmers David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Universi ...

argues that a theory of everything must explain

consciousness Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...

, that consciousness does not logically

supervene In philosophy, supervenience refers to a relation between sets of properties or sets of facts. X is said to supervene on Y if and only if some difference in Y is necessary for any difference in X to be possible. Some examples include: * Whether t ...

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 A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried W ...

or protophenomenal properties and psychophysical laws explaining the relationship between physical processes and conscious experience. He concludes that " ce 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", a 2002 essay in the ''

Journal of Evolution and Technology The Institute for Ethics and Emerging Technologies (IEET) is a technoprogressive think tank that seeks to "promote ideas about how technological progress can increase freedom, happiness, and human flourishing in democratic societies."Joseph R. ...

'', 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 Transhumanism is a philosophical and intellectual movement which advocates the enhancement of the human condition by developing and making widely available sophisticated technologies that can greatly enhance longevity and cognition. Transhuma ...

approach in which philosophers are "scaled up" by advanced technology into "super-intelligent beings" better able to pursue such a theory.

Criticism

In "Holistic Explanation and the Idea of a Grand Unified Theory", 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.

References

{{reflist