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.
Metaphysics is the branch of philosophy that examines the basic structure of reality. It is traditionally seen as the study of mind-independent features of the world, but some theorists view it as an inquiry into the fundamental categories of human understanding. Some philosophers, including Aristotle, designate metaphysics as first philosophy to suggest that it is more fundamental than other forms of philosophical inquiry.
In metaphysics, nominalism is the view that universals and abstract objects do not actually exist other than being merely names or labels. There are two main versions of nominalism. One denies the existence of universals – that which can be instantiated or exemplified by many particular things. The other version specifically denies the existence of abstract objects as such – objects that do not exist in space and time.
In metaphysics, a universal is what particular things have in common, namely characteristics or qualities. In other words, universals are repeatable or recurrent entities that can be instantiated or exemplified by many particular things. For example, suppose there are two chairs in a room, each of which is green. These two chairs share the quality of "chairness", as well as "greenness" or the quality of being green; in other words, they share two "universals". There are three major kinds of qualities or characteristics: types or kinds, properties, and relations. These are all different types of universals.
Reality is the sum or aggregate of all that is real or existent within the universe, as opposed to that which is only imaginary, nonexistent or nonactual. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, reality is the totality of a system, known and unknown.
Solipsism is the philosophical idea that only one's mind is sure to exist. As an epistemological position, solipsism holds that knowledge of anything outside one's own mind is unsure; the external world and other minds cannot be known and might not exist outside the mind.
Ownership is the state or fact of legal possession and control over property, which may be any asset, tangible or intangible. Ownership can involve multiple rights, collectively referred to as title, which may be separated and held by different parties.
Essence has various meanings and uses for different thinkers and in different contexts. It is used in philosophy and theology as a designation for the property or set of properties or attributes that make an entity the entity it is or, expressed negatively, without which it would lose its identity. Essence is contrasted with accident, which is a property or attribute the entity has accidentally or contingently, but upon which its identity does not depend.
In logic and philosophy, a property is a characteristic of an object; a red object is said to have the property of redness. The property may be considered a form of object in its own right, able to possess other properties. A property, however, differs from individual objects in that it may be instantiated, and often in more than one object. It differs from the logical/mathematical concept of class by not having any concept of extensionality, and from the philosophical concept of class in that a property is considered to be distinct from the objects which possess it. Understanding how different individual entities can in some sense have some of the same properties is the basis of the problem of universals.
In the philosophy of perception and philosophy of mind, direct or naïve realism, as opposed to indirect or representational realism, are differing models that describe the nature of conscious experiences; out of the metaphysical question of whether the world we see around us is the real world itself or merely an internal perceptual copy of that world generated by our conscious experience.
Modal realism is the view propounded by philosopher David Lewis that all possible worlds are real in the same way as is the actual world: they are "of a kind with this world of ours." It is based on four tenets: possible worlds exist, possible worlds are not different in kind from the actual world, possible worlds are irreducible entities, and the term actual in actual world is indexical, i.e. any subject can declare their world to be the actual one, much as they label the place they are "here" and the time they are "now".
Environmental hazards are those hazards that affect biomes or ecosystems. Well known examples include oil spills, water pollution, slash and burn deforestation, air pollution, ground fissures, and build-up of atmospheric carbon dioxide. Physical exposure to environmental hazards is usually involuntary
Haecceity is a term from medieval scholastic philosophy, first coined by followers of Duns Scotus to denote a concept that he seems to have originated: the irreducible determination of a thing that makes it this particular thing. Haecceity is a person's or object's thisness, the individualising difference between the concept "a man" and the concept "Socrates". In modern philosophy of physics, it is sometimes referred to as primitive thisness.
This glossary of philosophy is a list of definitions of terms and concepts relevant to philosophy and related disciplines, including logic, ethics, and theology.
Martin Heidegger, the 20th-century German philosopher, produced a large body of work that intended a profound change of direction for philosophy. Such was the depth of change that he found it necessary to introduce many neologisms, often connected to idiomatic words and phrases in the German language.
The following outline is provided as an overview of and topical guide to metaphysics:
A reference is a relationship between objects in which one object designates, or acts as a means by which to connect to or link to, another object. The first object in this relation is said to refer to the second object. It is called a name for the second object. The next object, the one to which the first object refers, is called the referent of the first object. A name is usually a phrase or expression, or some other symbolic representation. Its referent may be anything – a material object, a person, an event, an activity, or an abstract concept.
Documentality is the theory of documents that underlies the ontology of social reality put forward by the Italian philosopher Maurizio Ferraris. The theory gives to documents a central position within the sphere of social objects, conceived as distinct from physical and ideal objects. Ferraris argues that social objects are "social acts that have been inscribed on some kind of support", be it a paper document, a magnetic support, or even memory in people's heads. Thus the constitutive rule of social objects is that Object = Inscribed Act. Therefore, documents as inscriptions possessing social relevance and value embody the essential and prototypical features of any social object, and it is on this basis that it is possible to develop an ontology capable of classifying documents and their selective storage, beginning with the grand divide between strong documents, which make up social objects in the full sense, and weak documents, which are secondary derivatives and of lesser importance. This theory is inspired, on the one hand, by the reflection on the centrality of writing developed by Jacques Derrida and, on the other hand, by the theory of social acts devised by Adolf Reinach (1913) and the theory of linguistic acts by John L. Austin (1962).
An enemy or a foe is an individual or a group that is considered as forcefully adverse or threatening. The concept of an enemy has been observed to be "basic for both individuals and communities". The term "enemy" serves the social function of designating a particular entity as a threat, thereby invoking an intense emotional response to that entity. The state of being or having an enemy is enmity, foehood or foeship.
