Object
In philosophy, an object is any entity that can be the subject of thought, reference, or discourse, encompassing concrete things like physical bodies and electrons, abstract entities like numbers and properties, structured wholes like nations, and even fictional or nonexistent items like ghosts.[1] This broad conception contrasts with narrower historical usages, such as in medieval philosophy where objectum often denoted something thrown against the mind (as in opposition to the subject), but in modern philosophy, it has evolved to include whatever stands as a Gegenstand or counterpart to cognition, applying to both real and ideal domains.[1] A pivotal development occurs in Immanuel Kant's transcendental philosophy, where the concept of an object in general is identified as the highest and most abstract category, serving as the necessary correlate of any representation—whether through intuition or concept—without which cognition would lack unity or reference.[2] Kant distinguishes between quantificational objects (q-objects), which exist through absolute positing and are given in sensible intuition (e.g., "there is an object that falls under the concept F"), and representational objects (r-objects), which are what representations are about and can include thought-objects like negative noumena that we cannot sensibly intuit but can conceive.[2] This framework underscores objects' role in bridging appearances (phenomena) and things-in-themselves (noumena), limiting knowledge to the former while allowing thought of the latter.[2] Contemporary philosophy extends these ideas through object-oriented ontology (OOO), which posits a "flat" metaphysics where objects—real or sensual—are withdrawn from full human access and not reducible to their relations or components, challenging anthropocentric views in both analytic and continental traditions.[1] Philosophers like Graham Harman distinguish real objects (independent entities with withdrawn qualities) from sensual objects (experienced via relations), emphasizing that all objects, from quarks to myths, possess intrinsic reality beyond observation or use.[1] Such theories intersect with debates on ordinary objects (e.g., tables as mereological sums), abstract objects (e.g., universals vs. nominalism), and nonexistent objects (e.g., unicorns as intentional targets), highlighting the term's enduring centrality in metaphysics, epistemology, and ontology.[2]Philosophy and general concepts
Metaphysical and ontological definitions
In metaphysics, an object is generally understood as a being or entity that exists independently of other entities or human perception, serving as a fundamental unit of reality. This conception encompasses both concrete particulars, such as individual substances, and abstract entities, depending on the philosophical framework.[3] The historical development of the concept traces back to ancient philosophy, where Plato posited ideal Forms as transcendent, perfect objects that particular things in the sensible world imitate or participate in, providing the eternal essence beyond imperfect physical instances.[4] Aristotle, critiquing Plato's separation of Forms, developed hylomorphism, viewing objects as composites of matter (the underlying substrate) and form (the organizing principle that actualizes potential), as seen in substances like a bronze statue where bronze is the matter and the statue's shape is the form.[5] Ontologically, objects are often distinguished as particulars—unique, non-repeatable entities located in space and time—from universals, which are repeatable properties or kinds shared across multiple instances. This distinction fuels debates between realism, which affirms the independent existence of universals as real entities (e.g., the universal "redness" inhering in red objects), and nominalism, which denies universals, positing only particulars and treating shared properties as mere linguistic conventions or resemblances.[6][7] Epistemologically, the nature of objects involves how they are known or perceived. Immanuel Kant differentiated phenomena (objects as they appear to us, structured by space, time, and categories of understanding) from noumena (things-in-themselves, independent of our cognition and unknowable directly).[8] John Locke further elaborated this by distinguishing primary qualities of objects (such as shape, size, and solidity, which resemble ideas in the mind and exist independently) from secondary qualities (like color and taste, which are powers to produce sensations in perceivers and do not resemble the ideas they cause).[9][10] In twentieth-century phenomenology, Martin Heidegger reconceived objects in relation to human existence (Dasein), distinguishing "ready-to-hand" objects encountered practically as equipment in everyday use (e.g., a hammer as a tool in hammering) from "present-at-hand" objects analyzed theoretically after breakdown, emphasizing that objects reveal their being through our engaged involvement rather than detached observation.[11] These metaphysical ideas extend briefly to physical objects in science, where empirical entities are seen as manifestations of underlying independent beings.[3]Everyday and linguistic usage
In everyday language, an "object" commonly refers to a material thing that can be seen or touched, perceptible by the senses and distinct from abstract ideas or immaterial entities.[12] This usage emphasizes tangible items in the physical world, such as a book on a table or a stone in one's hand, which occupy space and can interact with other physical entities.[12] In linguistics, "object" plays a key role in sentence structure, particularly as the direct object, which is the noun, pronoun, or noun phrase that receives the action of a transitive verb, answering "what?" or "whom?" after the verb.[13] For instance, in the English sentence "The chef prepared the meal," "meal" serves as the direct object, completing the verb's meaning by indicating what was acted upon.[14] English typically identifies direct objects through word order (subject-verb-object), without explicit case markings.[15] Across languages, the direct object concept is universal, but expression varies: Romance languages like Spanish often use pronouns to replace direct objects (e.g., "lo" for masculine singular), while languages such as German or Latin employ accusative case endings to mark them morphologically.[15] In contrast, some agglutinative languages like Turkish attach suffixes directly to the object to indicate its role.[15] Cognitively, humans perceive and categorize objects through innate organizational processes, as described in Gestalt psychology, where sensory information is grouped into meaningful wholes rather than isolated parts.[16] Key Gestalt principles, such as figure-ground organization, enable the brain to distinguish an object (the figure) from its surrounding context (the ground), facilitating recognition—for example, identifying a tree amid a forest.[16] Principles like proximity (grouping nearby elements) and closure (filling gaps to form complete shapes) further aid in object categorization, allowing quick mental classification of everyday items like a smartphone or a vehicle without conscious effort.[17] These perceptual mechanisms underpin basic cognition, helping individuals navigate and interact with their environment efficiently.[18] Idiomatically, "object" extends beyond literal meanings in phrases that evoke emotional or social dynamics, such as "object of desire," which denotes a person, thing, or goal intensely coveted or pursued.[19] Similarly, "sex object" refers to an individual regarded primarily as a means of sexual gratification, often critiqued in discussions of dehumanization where personal agency is overlooked in favor of physical appeal.[20] These expressions highlight how "object" can imply passivity or target status in relational contexts, reflecting broader linguistic patterns of metaphorically applying concrete terms to abstract human experiences.Science, technology, and mathematics
Physics and natural sciences
In physics, a physical object is an identifiable entity composed of matter that possesses mass, occupies volume, and has a definite position in spacetime, characterized by a timelike spacetime interval that ensures its existence as a duration in spacetime.[21] In classical mechanics, such objects are often modeled as rigid bodies, where the distances between constituent particles remain fixed, allowing Newton's laws to describe their motion.[22] Newton's first law states that a physical object at rest remains at rest, and one in motion continues in uniform motion unless acted upon by an external force, reflecting its inertia proportional to mass.[23] The second law quantifies acceleration as force divided by mass (F = ma), applied to the center of mass of rigid bodies for translational motion, while the third law ensures internal forces cancel, enabling net external forces to govern overall dynamics.[23][22] In astronomy, celestial objects refer to naturally occurring physical entities in space, such as stars, planets, asteroids, and galaxies, studied as discrete units separated from their surroundings.[24] Planetary bodies in the Solar System exemplify these, including eight planets (Mercury through Neptune), five dwarf planets like Pluto and Eris, hundreds of moons, and thousands of asteroids and comets orbiting the Sun.[25] These objects maintain stable orbits due to gravitational interactions, with planets classified by composition—terrestrial (rocky, like Earth) or gas giants (like Jupiter)—and sizes ranging from Mercury's diameter of about 4,879 km to Jupiter's 142,984 km.[26] At subatomic scales, quantum mechanics treats particles like electrons and photons as fundamental objects exhibiting wave-particle duality, where they behave as discrete quanta with quantized properties such as energy levels in bound states.[27] These particles are described by wave functions that provide probabilities for position and momentum, rather than definite trajectories, yet they interact as localized entities in experiments like the double-slit interference.[27] In general relativity, massive objects such as stars and black holes curve spacetime, with the degree of curvature proportional to mass and inversely to distance, dictating the geodesic paths that objects follow as gravitational motion.[28] In biology, organisms serve as discrete objects, organized into cells that form the fundamental units of life, enclosed by membranes defining clear boundaries for metabolic and reproductive processes.[29] Unicellular organisms like bacteria or multicellular ones like humans exhibit traits such as growth, response to stimuli, and heredity, distinguishing them as independent entities in ecosystems.[29] In chemistry, molecules represent the smallest discrete units of chemical objects, consisting of two or more atoms bonded covalently, retaining the substance's properties while being electrically neutral.[30] Examples include diatomic oxygen (O₂) for homonuclear molecules and water (H₂O) for heteronuclear ones, where bonds determine structure and reactivity.[30]Computing and information technology
In object-oriented programming (OOP), an object is a fundamental unit, representing an instance of a class with a unique identity that encapsulates both data attributes (state) and associated methods (behavior) for manipulating that data. This concept, pioneered by Alan Kay in the development of Smalltalk, views objects as entities that communicate via message passing to simulate real-world interactions, promoting modularity and reusability in software design.[31][32] In languages like Java, an object is created using thenew keyword, such as Car myCar = new Car();, where the Car class defines the object's state (e.g., speed, color) and behavior (e.g., accelerate method).[32] Similarly, in Python, all data is represented as objects, instantiated via class constructors like class Dog: pass; dog = Dog(), allowing seamless integration of attributes and methods.[33]
Central to OOP are three key principles: encapsulation, inheritance, and polymorphism. Encapsulation bundles an object's internal state and operations, restricting direct access to promote data integrity and abstraction, as seen in private fields and public methods in class definitions. Inheritance enables a subclass to acquire attributes and methods from a superclass, facilitating code reuse; for example, a SportsCar class in Java might extend Car to add specialized features like turbo boost. Polymorphism allows objects of different classes to be treated interchangeably through a common interface, such as overriding methods in subclasses to achieve runtime flexibility, exemplified by Python's method resolution order in multiple inheritance scenarios.[34] These principles, unified in OOP languages, support scalable software architectures by modeling complex systems as hierarchies of interacting objects.
In databases, objects extend beyond programming to object-relational models, which integrate OOP concepts with relational structures to handle complex data types like multimedia or spatial information. Object-relational database management systems (ORDBMS) support inheritance and encapsulation for entities, allowing queries on object attributes alongside traditional SQL operations, as implemented in systems like PostgreSQL.[35] Object-relational mapping (ORM) frameworks further bridge this gap by automatically converting database records into programming objects, enabling developers to interact with persistent data using familiar OOP syntax without writing raw SQL.
In file systems and cloud computing, object storage treats data as discrete objects comprising files and metadata, optimized for scalability and unstructured content like backups or media. Amazon Simple Storage Service (S3) exemplifies this, storing objects in buckets with unique keys, providing durable access without hierarchical directories, which supports massive-scale applications in big data environments.[36][37]
In emerging technologies as of 2025, objects play a pivotal role in artificial intelligence, particularly computer vision, where object detection algorithms identify and classify real-world entities in images or video. The YOLO (You Only Look Once) framework, introduced in 2015, treats detection as a single regression problem to predict bounding boxes and class probabilities directly, enabling real-time performance; subsequent versions like YOLOv10 (2024) and YOLOv12 (2025) have refined accuracy and efficiency for applications in autonomous vehicles and surveillance.[38][39][40] This digital representation of objects draws brief inspiration from physical modeling in simulations but focuses on computational efficiency for pattern recognition.[39]