Existence has been variously defined by sources. In common usage, it is the world one is aware or conscious of through one's senses, and that persists independently in one's absence. Other definitions describe it as everything that 'is', or more simply, everything. Some define it to be everything that most people believe in. Aristotle relates the concept to causality.

Ontology is the philosophical study of the nature of being, existence or reality in general, as well as of the basic categories of being and their relations. Traditionally listed as a part of the major branch of philosophy known as metaphysics, ontology deals with questions concerning what entities exist or can be said to exist, and how such entities can be grouped, related within a hierarchy, and subdivided according to similarities and differences. A lively debate continues about the existence of God.

Epistemology studies criteria of truth, defining "primary truths" inherently accepted in the investigation of knowledge. The first is existence. It is inherent in every analysis. Its self-evident, a priori nature cannot be consistently doubted, since a person objecting to existence according to some standard of proof must implicitly accept the standard's existence as a premise.

Materialism holds that the only thing that exists is matter, that all things are composed of material, and all phenomena (including consciousness) are the result of material interactions.

Life is a characteristic that distinguishes objects that have self-sustaining biological processes from those that do not – either because such functions have ceased (death), or else because they lack such functions and are classified as "inanimate".

Read more about Existence:  Etymology, Historical Conceptions, Predicative Nature, Modern Approaches, Dharmic "middle Way" View

Other articles related to "existence":

Facticity - Heidegger
... Heidegger discusses facticity as the thrownness (Geworfenheit) of individual existence, which is to say we are "thrown into the world." By this, he is not only referring to a brute fact, or the factuality ... is something that already informs and has been taken up in existence, even if it is unnoticed or left unattended ... The thrownness of human existence (or Dasein) is accordingly disclosed through moods ...
Brisbane Line - Post-war Claims
... Proponents of the existence of the Brisbane Line proposal often refer to the existence of concrete tank traps near places such as Tenterfield, which were constructed in the late 1930s ... However the existence of defences in New South Wales did not suggest any intention of abandoning other parts of Australia ...
Moment Problem - Existence
... similar form is necessary and sufficient for the existence of a measure supported on a given interval ... Thus the existence of the measure is equivalent to (1) ...
Karma In Jainism - Scientific Interpretation
... research Jain philosopher-monks postulated the existence of karma as subtle and microscopic particles that cannot be perceived by senses, some two millennia before modern science proved the ... is not yet proven, one only needs to recall that science found proof of the existence of molecules and atoms only the 19th and 20th century ... leptons only a hundred years ago may have been dismissed, though such theories were in existence ...
Existence - Dharmic "middle Way" View
150 - 250 CE) largely advanced existence concepts and founded the Madhyamaka school of Mahāyāna Buddhism ... philosophy, Anicca (Sanskrit anitya) or "impermanence" describes existence ... While the appearance and relative existence of the leaf ceases, the components that formed the leaf become particulate material that goes on to form new plants ...

Famous quotes containing the word existence:

    The hour when you say, “What does my happiness matter? It is poverty and filth, and a wretched complacency. Yet my happiness should justify existence itself!”
    Friedrich Nietzsche (1844–1900)

    The individual who has to justify his existence by his own efforts is in eternal bondage to himself.
    Eric Hoffer (1902–1983)

    We go on dating from Cold Fridays and Great Snows; but a little colder Friday, or greater snow would put a period to man’s existence on the globe.
    Henry David Thoreau (1817–1862)