In grammar, tense is a category that expresses time reference. Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns.
Heraclitus was an ancient Greek pre-Socratic philosopher from the city of Ephesus, which was then part of the Persian Empire.
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred to as a fourth dimension, along with three spatial dimensions.
In the philosophy of space and time, eternalism is an approach to the ontological nature of time, which takes the view that all existence in time is equally real, as opposed to presentism or the growing block universe theory of time, in which at least the future is not the same as any other time. Some forms of eternalism give time a similar ontology to that of space, as a dimension, with different times being as real as different places, and future events are "already there" in the same sense other places are already there, and that there is no objective flow of time.
Impermanence, also known as the philosophical problem of change, is a philosophical concept addressed in a variety of religions and philosophies. In Eastern philosophy it is notable for its role in the Buddhist three marks of existence. It is also an element of Hinduism. In Western philosophy it is most famously known through its first appearance in Greek philosophy in the writings of Heraclitus and in his doctrine of panta rhei. In Western philosophy the concept is also referred to as becoming.
Modal logic is a kind of logic used to represent statements about necessity and possibility. It plays a major role in philosophy and related fields as a tool for understanding concepts such as knowledge, obligation, and causation. For instance, in epistemic modal logic, the formula can be used to represent the statement that is known. In deontic modal logic, that same formula can represent that is a moral obligation. Modal logic considers the inferences that modal statements give rise to. For instance, most epistemic logics treat the formula as a tautology, representing the principle that only true statements can count as knowledge.
Counterfactual conditionals are conditional sentences which discuss what would have been true under different circumstances, e.g. "If Peter believed in ghosts, he would be afraid to be here." Counterfactuals are contrasted with indicatives, which are generally restricted to discussing open possibilities. Counterfactuals are characterized grammatically by their use of fake tense morphology, which some languages use in combination with other kinds of morphology including aspect and mood.
The Eleatics were a group of pre-Socratic philosophers and school of thought in the 5th century BC centered around the ancient Greek colony of Elea, located in present-day Campania in southern Italy, then known as Magna Graecia.
Philosophy of space and time is the branch of philosophy concerned with the issues surrounding the ontology and epistemology of space and time. While such ideas have been central to philosophy from its inception, the philosophy of space and time was both an inspiration for and a central aspect of early analytic philosophy. The subject focuses on a number of basic issues, including whether time and space exist independently of the mind, whether they exist independently of one another, what accounts for time's apparently unidirectional flow, whether times other than the present moment exist, and questions about the nature of identity.
The Kalam cosmological argument is a modern formulation of the cosmological argument for the existence of God. It is named after the Kalam, from which its key ideas originated. William Lane Craig was principally responsible for giving new life to the argument in the 20th century, due to his book The Kalām Cosmological Argument (1979), among other writings.
"The Unreality of Time" is the best-known philosophical work of the Cambridge idealist J. M. E. McTaggart (1866–1925). In the argument, first published as a journal article in Mind in 1908, McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient. A slightly different version of the argument appeared in 1927 as one of the chapters in the second volume of McTaggart's greatest work, The Nature of Existence.
Philosophical presentism is the view that only present entities exist. According to presentism, there are no past or future entities. In a sense, the past and the future do not exist for presentists—past events have happened and future events will happen, but neither exist at all since they do not exist now. Presentism is a view about temporal ontology that contrasts with eternalism—the view that past, present and future entities exist —and with no-futurism—the view that only past and present entities exist.
In philosophy, four-dimensionalism is the ontological position that an object's persistence through time is like its extension through space. Thus, an object that exists in time has temporal parts in the various subregions of the total region of time it occupies, just like an object that exists in a region of space has at least one part in every subregion of that space.
In contemporary metaphysics, temporal parts are the parts of an object that exist in time. A temporal part would be something like "the first year of a person's life", or "all of a table from between 10:00 a.m. on June 21, 1994 to 11:00 p.m. on July 23, 1996". The term is used in the debate over the persistence of material objects. Objects typically have parts that exist in space—a human body, for example, has spatial parts like hands, feet, and legs. Some metaphysicists believe objects have temporal parts as well.
The B-theory of time, also called the "tenseless theory of time", is one of two positions regarding the temporal ordering of events in the philosophy of time. B-theorists argue that the flow of time is only a subjective illusion of human consciousness, that the past, present, and future are equally real, and that time is tenseless: temporal becoming is not an objective feature of reality. Therefore, there is nothing privileged about the present, ontologically speaking.
The growing block universe theory of time states that the past and present both exist, and the future as yet does not. The present is an objective property, to be compared with a moving spotlight. By the passage of time more of the world comes into being; therefore, the block universe is said to be growing. The growth of the block is supposed to happen in the present, a very thin slice of spacetime, where more of spacetime is continually coming into being. Growing block theory should not be confused with block universe theory, also known as eternalism.
John McTaggart Ellis McTaggart was an English idealist metaphysician. For most of his life McTaggart was a fellow and lecturer in philosophy at Trinity College, Cambridge. He was an exponent of the philosophy of Georg Wilhelm Friedrich Hegel and among the most notable of the British idealists. McTaggart is known for "The Unreality of Time" (1908), in which he argues that time is unreal. The work has been widely discussed through the 20th century and into the 21st.
The Hopi time controversy is the academic debate about how the Hopi language grammaticalizes the concept of time, and about whether the differences between the ways the English and Hopi languages describe time are an example of linguistic relativity or not. In popular discourse the debate is often framed as a question about whether the Hopi have a concept of time.
Relations are ways in which several entities stand to each other. They usually connect distinct entities but some associate an entity with itself. The adicity of a relation is the number of entities it connects. The direction of a relation is the order in which the elements are related to each other. The converse of a relation carries the same information and has the opposite direction, like the contrast between "two is less than five" and "five is greater than two". Both relations and properties express features in reality with a key difference being that relations apply to several entities while properties belong to a single entity.
Philosophy of motion is a branch of philosophy concerned with exploring questions on the existence and nature of motion. The central questions of this study concern the epistemology and ontology of motion, whether motion exists as we perceive it, what is it, and, if it exists, how does it occur. The philosophy of motion is important in the study of theories of change in natural systems and is closely connected to studies of space and time in philosophy.
