MetaphysicsMetaphysics is the branch of philosophy that studies the fundamental nature of reality. This includes the first principles of: being or existence, identity, change, space and time, cause and effect, necessity, actuality, and possibility. Metaphysics is considered one of the four main branches of philosophy, along with epistemology, logic, and ethics. It includes questions about the nature of consciousness and the relationship between mind and matter, between substance and attribute, and between potentiality and actuality.
Cogito, ergo sumThe Latin cogito, ergo sum, usually translated into English as "I think, therefore I am", is the "first principle" of René Descartes's philosophy. He originally published it in French as je pense, donc je suis in his 1637 Discourse on the Method, so as to reach a wider audience than Latin would have allowed. It later appeared in Latin in his Principles of Philosophy, and a similar phrase also featured prominently in his Meditations on First Philosophy. The dictum is also sometimes referred to as the cogito.
MonismMonism 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., in Neoplatonism everything is derived from The One. In this view only the One is ontologically basic or prior to everything else. Existence monism posits that, strictly speaking, there exists only a single thing, the universe, which can only be artificially and arbitrarily divided into many things.
Law of noncontradictionIn logic, the law of non-contradiction (LNC) (also known as the law of contradiction, principle of non-contradiction (PNC), or the principle of contradiction) states that contradictory propositions cannot both be true in the same sense at the same time, e. g. the two propositions "p is the case" and "p is not the case" are mutually exclusive. Formally, this is expressed as the tautology ¬(p ∧ ¬p). The law is not to be confused with the law of excluded middle which states that at least one, "p is the case" or "p is not the case" holds.
Gottfried Wilhelm LeibnizGottfried Wilhelm (von) Leibniz ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is a prominent figure in both the history of philosophy and the history of mathematics. He wrote works on philosophy, theology, ethics, politics, law, history and philology. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in probability theory, biology, medicine, geology, psychology, linguistics and computer science.
EpicurusEpicurus (ˌɛpɪˈkjʊərəs, ; Ἐπίκουρος ; 341–270 BC) was an ancient Greek philosopher and sage who founded Epicureanism, a highly influential school of philosophy. He was born on the Greek island of Samos to Athenian parents. Influenced by Democritus, Aristippus, Pyrrho, and possibly the Cynics, he turned against the Platonism of his day and established his own school, known as "the Garden", in Athens. Epicurus and his followers were known for eating simple meals and discussing a wide range of philosophical subjects.
ConsciousnessConsciousness, at its simplest, is awareness of internal and external existence. However, its nature has led to millennia of analyses, explanations and debates by philosophers, theologians, linguists, and scientists. Opinions differ about what exactly needs to be studied or even considered consciousness. In some explanations, it is synonymous with the mind, and at other times, an aspect of mind. In the past, it was one's "inner life", the world of introspection, of private thought, imagination and volition.
EssenceEssence (essentia) is a polysemic term, having various meanings and uses. It is used in philosophy and theology as a designation for the property or set of properties or attributes that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it loses its identity. Essence is contrasted with accident: a property or attribute the entity or substance has contingently, without which the substance can still retain its identity.
Modal realismModal 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".
Relations (philosophy)Relations are ways in which things, the relata, stand to each other. Relations are in many ways similar to properties in that both characterize the things they apply to. Properties are sometimes treated as a special case of relations involving only one relatum. In philosophy (especially metaphysics), theories of relations are typically introduced to account for repetitions of how several things stand to each other. The concept of relation has a long and complicated history.
