Concepts in the context of "Propositions"

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.

Ontology is the philosophical discipline studying the nature and types of existence. Singular existence is the existence of individual entities while general existence refers to the existence of concepts or universals. Entities present in space and time have concrete existence in contrast to abstract entities, like numbers and sets. Other distinctions are between possible, contingent, and necessary existence and between physical and mental existence. The common view is that an entity either exists or not with nothing in between, but some philosophers say that there are degrees of existence, meaning that some entities exist to a higher degree than others.

Cognitions are mental activities that deal with knowledge. They encompass psychological processes that acquire, store, retrieve, transform, or otherwise use information. Cognitions are a pervasive part of mental life, helping individuals understand and interact with the world.

Cognitive processes are typically categorized by their function. Perception organizes sensory information about the world, interpreting physical stimuli, such as light and sound, to construct a coherent experience of objects and events. Attention prioritizes specific aspects while filtering out irrelevant information. Memory is the ability to retain, store, and retrieve information, including working memory and long-term memory. Thinking encompasses psychological activities in which concepts, ideas, and mental representations are considered and manipulated. It includes reasoning, concept formation, problem-solving, and decision-making. Many cognitive activities deal with language, including language acquisition, comprehension, and production. Metacognition involves knowledge about knowledge or mental processes that monitor and regulate other mental processes. Classifications also distinguish between conscious and unconscious processes and between controlled and automatic ones.

Normativity concerns the standards of what people ought to do, believe, or value. It is a quality of rules, judgments, or concepts that prescribe how things should be or what individuals may, must, or must not do. Normative claims express what ought to be the case, such as "you should not smoke". They contrast with descriptive claims about what is the case, such as "you smoked yesterday". Normativity shapes many everyday activities, such as decision-making, evaluating outcomes, criticizing others, and justifying actions.

Researchers discuss many types of normativity. Practical normativity is about what to do, while theoretical normativity concerns what to believe. Deontic normativity deals with what is allowed, required, or forbidden, whereas evaluative normativity addresses the values underlying normative assessments. Objective normativity encompasses requirements that do not depend on personal views, in contrast to subjective normativity, which is about standards relative to subjective perspectives. A normative assessment is pro tanto if it is partial by only taking certain aspects into account, unlike all-things-considered judgments, which factor in all relevant aspects. Other distinctions are based on the domain of assessment, such as moral, social, legal, and linguistic norms. Some categories may overlap, and there are academic disagreements about whether all these types are genuine forms of normativity.

Propositions are the meanings of declarative sentences, objects of beliefs, and bearers of truth values. They explain how different sentences, like the English "Snow is white" and the German "Schnee ist weiß", can have identical meaning by expressing the same proposition. Similarly, they ground the fact that different people can share a belief by being directed at the same content. True propositions describe the world as it is, while false ones fail to do so. Researchers distinguish types of propositions by their informational content and mode of assertion, such as the contrasts between affirmative and negative propositions, between universal and existential propositions, and between categorical and conditional propositions.

Many theories of the nature and roles of propositions have been proposed. Realists argue that propositions form part of reality, a view rejected by anti-realists. Non-reductive realists understand propositions as a unique kind of entity, whereas reductive realists analyze them in terms of other entities. One proposal sees them as sets of possible worlds, reflecting the idea that understanding a proposition involves grasping the circumstances under which it would be true. A different suggestion focuses on the individuals and concepts to which a proposition refers, defining propositions as structured entities composed of these constituents. Other accounts characterize propositions as specific kinds of properties, relations, or states of affairs. Philosophers also debate whether propositions are abstract objects outside space and time, psychological entities dependent on mental activity, or linguistic entities grounded in language. Paradoxes challenge the different theories of propositions, such as the liar's paradox. The study of propositions has its roots in ancient philosophy, with influential contributions from Aristotle and the Stoics, and later from William of Ockham, Gottlob Frege, and Bertrand Russell.