Свойства объектов: логический и философский анализ.

Differentiating and characterizing feature
In logic and philosophy (especially metaphysics), 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 (or particulars) can in some sense have some of the same properties is the basis of the problem of universals.

A property is any member of a class of entities that are capable of being attributed to objects. Terms similar to property include predicable, attribute, quality, feature, characteristic, type, exemplifiable, predicate, and intensional entity. Edward Jonathan Lowe even treated instantiation, characterization and exemplification as three separate kinds of predication. the property of being nonexistent, the property of being identical to Socrates, One way to spell this out is in terms of exact, repeatable, instantiations known as universals. The other realist position asserts that properties are particulars (tropes), which are unique instantiations in individual objects that merely resemble one another to various degrees. Transcendent realism, proposed by Plato and favored by Bertrand Russell, asserts that properties exist even if uninstantiated. Categorical properties concern what something is like, e. g. what qualities it has. Dispositional properties, on the other hand, involve what powers something has, what it is able to do, even if it is not actually doing it. According to categoricalism, dispositions reduce to causal bases. On this view, the fragility of a wine glass, a dispositional property, is not a fundamental feature of the glass since it can be explained in terms of the categorical property of the glass's micro structural composition. Dispositionalism, on the other hand, asserts that a property is nothing more than a set of causal powers. Metaphysical idealism, by contrast, claims that "something mental (the mind, spirit, reason, will) is the ultimate foundation of all reality, or even exhaustive of reality."

An intrinsic property is a property that an object or a thing has of itself, independently of other things, including its context. An extrinsic (or relational) property is a property that depends on a thing's relationship with other things. The latter is sometimes also called an attribute, since the value of that property is given to the object via its relation with another object. For example, mass is a physical intrinsic property of any physical object, whereas weight is an extrinsic property that varies depending on the strength of the gravitational field in which the respective object is placed. Another example of a relational property is the name of a person (an attribute given by the person's parents).

In classical Aristotelian terminology, a property (Greek: idion, Latin: proprium) is one of the predicables. It is a non essential quality of a species (like an accident), but a quality which is nevertheless characteristically present in members of that species. For example, "ability to laugh" may be considered a special characteristic of human beings. However, "laughter" is not an essential quality of the species human, whose Aristotelian definition of "rational animal" does not require laughter. Therefore, in the classical framework, properties are characteristic qualities that are not truly required for the continued existence of an entity but are, nevertheless, possessed by the entity.

A property may be classified as either determinate or determinable. A determinable property is one that can get more specific. For example, color is a determinable property because it can be restricted to redness, blueness, etc. A determinate property is one that cannot become more specific. This distinction may be useful in dealing with issues of identity.

Impure properties are properties that, unlike pure properties, involve reference to a particular substance in their definition. So, for example, being a wife is a pure property while being the wife of Socrates is an impure property due to the reference to the particular "Socrates". Sometimes, the terms qualitative and non qualitative are used instead of pure and impure. Most but not all impure properties are extrinsic properties. This distinction is relevant for the principle of identity of indiscernibles, which states that two things are identical if they are indiscernible, i. e. if they share all their properties.

The ontological fact that something has a property is typically represented in language by applying a predicate to a subject. However, taking any grammatical predicate whatsoever to be a property, or to have a corresponding property, leads to certain difficulties, such as Russell's paradox and the Grelling–Nelson paradox. Moreover, a real property can imply a host of true predicates: for instance, if X has the property of weighing more than 2 kilos, then the predicates " weighs more than 1.9 kilos", " weighs more than 1.8 kilos", etc., are all true of it. Other predicates, such as "is an individual", or "has some properties" are uninformative or vacuous. There is some resistance to regarding such so called "Cambridge properties" as legitimate. These properties in the widest sense are sometimes referred to as abundant properties. They are contrasted with sparse properties, which include only properties "responsible for the objective resemblances and causal powers of things".

The traditional conception of similarity holds that properties are responsible for similarity: two objects are similar because they have a property in common. The more properties they share, the more similar they are. They resemble each other exactly if they share all their properties. For this conception of similarity to work, it is important that only properties relevant to resemblance are taken into account, sometimes referred to as sparse properties in contrast to abundant properties. Relations are true of several particulars, or shared amongst them. Thus the relation " is taller than " holds "between" two individuals, who would occupy the two ellipses (' '). Relations can be expressed by N place predicates, where N is greater than 1. Relations should be distinguished from relational properties. For example, marriage is a relation since it is between two people, but being married to X is a relational property had by a certain person since it concerns only one person. Some philosophers believe that all relations are external, leading to a scepticism about relations in general, on the basis that external relations have no fundamental existence.