Truthmaker theory is "the branch of metaphysics that explores the relationships between what is true and what exists."
A truthmaker for a truthbearer is that entity in virtue of which the truthbearer is true. Philosophers have speculated on the question whether every truthbearer requires a truthmaker. Parmenides' classic claim that what does not exist cannot be thought about has been read as a claim that every truthbearer must have a truthmaker, since otherwise the truthbearer is not about anything. A falsemaker for a proposition is that existent reality in virtue of which that proposition is false, assuming it is false.
Parmenides of Elea was a pre-Socratic Greek philosopher from Elea in Magna Graecia. Parmenides has been considered the founder of metaphysics or ontology and has influenced the whole history of Western philosophy. He was the founder of the Eleatic school of philosophy, which also included Zeno of Elea and Melissus of Samos. Zeno's paradoxes of motion were to defend Parmenides' view.
In philosophy, a proposition is a tentative and conjectural relationship between constructs that is stated in a declarative form. An example of a proposition is: “An increase in student intelligence causes an increase in their academic achievement.” This declarative statement does not have to be true, but must be empirically testable using data, so that we can judge whether it is true or false. Propositions are generally derived based on deductive logic or empirical observation (induction). Because propositions are associations between abstract constructs, they cannot be tested directly. Instead, they are tested indirectly by examining the relationship between corresponding measures (variables) of those constructs. The empirical formulation of propositions, stated as relationships between variables, is called hypotheses. The term proposition has a broad use in contemporary analytic philosophy. It is used to refer to some or all of the following: the primary bearers of truth-value, the objects of belief and other "propositional attitudes", the referents of that-clauses, and the meanings of declarative sentences. Propositions are the sharable objects of attitudes and the primary bearers of truth and falsity. This stipulation rules out certain candidates for propositions, including thought- and utterance-tokens which are not sharable, and concrete events or facts, which cannot be false.
In "Truth-Makers" (1984), Kevin Mulligan, Peter Simons and Barry Smith introduced the truth-maker idea as a contribution to the correspondence theory of truth. Logically atomic empirical sentences such as "John kissed Mary" have truthmakers, typically events or tropes corresponding to the main verbs of the sentences in question. Mulligan et al. explore extensions of this idea to sentences of other sorts, but they do not embrace any position of truthmaker maximalism, according to which every truthbearer has a truthmaker.
Kevin Mulligan is a British philosopher, working on ontology, the philosophy of mind, and Austrian philosophy. He is currently Honorary Professor at the University of Geneva, Full Professor at the Università della Svizzera italiana, Director of Research at the Institute of Philosophy of Lugano, member of the Academia Europaea and of the Royal Swedish Academy of Letters. He is also known for his work with Peter Simons and Barry Smith on metaphysics, Austrian and Polish philosophy.
Peter M. Simons, is a British philosopher and a retired professor of philosophy at Trinity College Dublin.
Barry Smith is an academic working in the fields of ontology and biomedical informatics. Smith is the author of more than 600 scientific publications, including 15 authored or edited books.
This maximalist position leads to philosophical difficulties, such as the question of what the truthmaker for an ethical, modal or mathematical truthbearer could be. Of course someone who is deeply enough committed to truthmakers and who simultaneously doubts that a truthmaker could be found for a certain kind of truthbearer will simply deny that that truthbearer could be true. Those who find the Parmenidean insight sufficiently compelling often take it to be a particularly enlightening metaphysical pursuit to search for truthmakers of these kinds of propositions.
Ethics or moral philosophy is a branch of philosophy that involves systematizing, defending, and recommending concepts of right and wrong conduct. The field of ethics, along with aesthetics, concerns matters of value, and thus comprises the branch of philosophy called axiology.
Modal logic is a type of formal logic primarily developed in the 1960s that extends classical propositional and predicate logic to include operators expressing modality. A modal—a word that expresses a modality—qualifies a statement. For example, the statement "John is happy" might be qualified by saying that John is usually happy, in which case the term "usually" is functioning as a modal. The traditional alethic modalities, or modalities of truth, include possibility, necessity, and impossibility. Other modalities that have been formalized in modal logic include temporal modalities, or modalities of time, deontic modalities, epistemic modalities, or modalities of knowledge and doxastic modalities, or modalities of belief.
Mathematics includes the study of such topics as quantity, structure, space, and change. It has no generally accepted definition.
Another difficulty for the claim that every truthbearer has a truthmaker is with negations of existential propositions (or, equivalently, universal propositions). What entity makes it true that unicorns do not exist? Proposals include the totality of all things, or some worldly state of affairs such as x1's not being a unicorn, x2's not being a unicorn, ..., and everything's being x1, or x2, or ... (the latter suggestion is due to Richard M. Gale).
David Lewis has proposed a more moderate version of the truthmaker theory on which truthmakers are only required for positive propositions (e.g., there must be a truthmaker for the proposition that there are horses, but not for the equally true proposition that there are no unicorns). What makes a negative proposition p true is the lack of a falsemaker for it, i.e., the lack of a truthmaker for the negation of p. Thus what makes it true that there are no unicorns is the lack of a truthmaker for the proposition that there are unicorns, i.e., the lack of unicorns. This may be what Protagoras was getting at when he said that to speak truly is to say of what is that it is and of what is not that it is not.
Protagoras was a pre-Socratic Greek philosopher. He is numbered as one of the sophists by Plato. In his dialogue Protagoras, Plato credits him with inventing the role of the professional sophist.
Truthmaker theorists differ as to what entities are the truthmakers of various truthbearers. Some say that the truthmaker of the proposition that Socrates is sitting (assuming he is) is Socrates' being seated (whatever exactly that might turn out to be on the correct ontology) and in general the truthmaker of the truthbearer expressed by a sentence s can be denoted by the participial nominalization of s. Others will say that the truthmaker of the proposition that Socrates is sitting is just Socrates himself. In any case, the truthmaker is supposed to be something concrete, and on the first view is that whose existence is reported by the truthbearer and on the second view is that which the truthbearer is about.
While the existence of truthmakers may seem an abstruse question, concrete instances are at the heart of a number of philosophical issues. Thus, J. L. Mackie has argued that the truthmakers of moral claims would be "queer entities", too strange to exist, and hence all moral claims are false. Alternatively, a divine command metaethicist may insist that the only possible candidate for a truthmaker of a moral claim is a command from a perfect God, and hence if moral claims are true and a truthmaker theory holds, then God exists. Thus the disagreement between various metaethical schools is in part a disagreement over what kinds of truthmakers moral claims would have if these claims were true and over whether such truthmakers exist.
Epistemology is the branch of philosophy concerned with the theory of knowledge.
Existence is the ability of an entity to interact with physical or mental reality.
In logic, the law of non-contradiction (LNC) states that contradictory propositions cannot both be true in the same sense at the same time, e. g. the two propositions "A is B" and "A is not B" are mutually exclusive. Formally this is expressed as the tautology ~(p & ~p).
In logic, the law of excluded middle states that for any proposition, either that proposition is true or its negation is true. It is one of the so called three laws of thought, along with the law of noncontradiction, and the law of identity. The law of excluded middle is logically equivalent to the law of noncontradiction by De Morgan's laws. However, no system of logic is built on just these laws, and none of these laws provide inference rules, such as modus ponens or De Morgan's laws.
Metaphysics is the branch of philosophy that examines the fundamental nature of reality, including the relationship between mind and matter, between substance and attribute, and between potentiality and actuality. The word "metaphysics" comes from two Greek words that, together, literally mean "after or behind or among [the study of] the natural". It has been suggested that the term might have been coined by a first century CE editor who assembled various small selections of Aristotle’s works into the treatise we now know by the name Metaphysics.
Meta-ethics is the branch of ethics that seeks to understand the nature of ethical properties, statements, attitudes, and judgments. Meta-ethics is one of the three branches of ethics generally studied by philosophers, the others being normative ethics and applied ethics.
An ontological commitment refers to a relation between a language and certain objects postulated to be extant by that language. The 'existence' referred to need not be 'real', but exist only in a universe of discourse. As an example, legal systems use vocabulary referring to 'legal persons' that are collective entities that have rights. One says the legal doctrine has an ontological commitment to non-singular individuals. In information systems and artificial intelligence, where an ontology refers to a specific vocabulary and a set of explicit assumptions about the meaning and usage of these words, then an ontological commitment is an agreement to use the shared vocabulary in a coherent and consistent manner within a specific context. In philosophy a "theory is ontologically committed to an object only if that object occurs in all the ontologies of that theory"
Scientific realism is the view that the universe described by science is real regardless of how it may be interpreted.
Cognitivism is the meta-ethical view that ethical sentences express propositions and can therefore be true or false, which noncognitivists deny. Cognitivism is so broad a thesis that it encompasses moral realism, ethical subjectivism, and error theory.
In epistemology, the correspondence theory of truth states that the truth or falsity of a statement is determined only by how it relates to the world and whether it accurately describes that world.
In logic, syntax is anything having to do with formal languages or formal systems without regard to any interpretation or meaning given to them. Syntax is concerned with the rules used for constructing, or transforming the symbols and words of a language, as contrasted with the semantics of a language which is concerned with its meaning.
In metaphysics, realism about a given object is the view that this object exists in reality independently of our conceptual scheme. In philosophical terms, these objects are ontologically independent of someone's conceptual scheme, perceptions, linguistic practices, beliefs, etc.
In philosophy, universality is the idea that universal facts exist and can be progressively discovered, as opposed to relativism. In certain theologies, universalism is the quality ascribed to an entity whose existence is consistent throughout the universe, whose being is independent of and unconstrained by the events and conditions that compose the universe, such as entropy and physical locality.
A truth-bearer is an entity that is said to be either true or false and nothing else. The thesis that some things are true while others are false has led to different theories about the nature of these entities. Since there is divergence of opinion on the matter, the term truth-bearer is used to be neutral among the various theories. Truth-bearer candidates include propositions, sentences, sentence-tokens, statements, concepts, beliefs, thoughts, intuitions, utterances, and judgements but different authors exclude one or more of these, deny their existence, argue that they are true only in a derivative sense, assert or assume that the terms are synonymous, or seek to avoid addressing their distinction or do not clarify it.
The term "trope" is both a term which denotes figurative and metaphorical language and one which has been used in various technical senses. The term trope derives from the Greek τρόπος (tropos), "a turn, a change", related to the root of the verb τρέπειν (trepein), "to turn, to direct, to alter, to change"; this means that the term is used metaphorically to denote, among other things, metaphorical language. Perhaps the term can be explained as meaning the same thing as a turn of phrase in its original sense.
The following outline is provided as an overview of and topical guide to metaphysics:
In logic, the term statement is variously understood to mean either:
Objectivity is a philosophical concept of being true independently from individual subjectivity caused by perception, emotions, or imagination. A proposition is considered to have objective truth when its truth conditions are met without bias caused by a sentient subject. Scientific objectivity refers to the ability to judge without partiality or external influence, sometimes used synonymously with neutrality.
Ontological priority is a concept in philosophy where one entity is prior to another in being.