Transformation of Quantitative Into Qualitative Changes

a basic law of materialist dialectics, according to which a change in the quality of an object occurs when the accumulation of quantitative changes reaches a certain limit. The law reveals the most general mechanism of development. First formulated on an objective idealist basis by G. Hegel, it was creatively developed along dialectical materialist lines by the classical Marxist-Leninist writers.

The law is objective and universal in character. Its content is revealed by all the categories of dialectics, especially the categories of quality, quantity, and measure. Any quantitative change appears as a change in the elements of a system. The degree of difference between the old quality and the new one depends on the quantitative changes in the object under investigation. “Qualitative changes—in a manner exactly fixed for each individual case—can only occur by the quantitative addition or quantitative subtraction of matter or motion (so-called energy)” (F. Engels, in K. Marx and F. Engels, Soch., 2nd ed., vol. 20, p. 385). The appearance of a new quality means essentially the appearance of an object with new laws and a measure with a different quantitative specificity. The profundity of the qualitative changes involved may vary. It may be limited to a single level of the given form of motion or may go beyond this; our ancestor the anthropoid rose from the biological level to the social, for example.

Radical change in a given quality—the shattering of the old and the birth of the new—constitutes a leap. A leap is a transition from an old quality to a new one, from one measure to another. “What distinguishes the dialectical transition from the undialectical transition? The leap. The contradiction. The interruption of gradualness” (V. I. Lenin, Poln. sobr. soch, 5th ed., vol. 29, p. 256). The transformation of a phenomenon from one qualitative state to another constitutes the unity of extinction and origination, of being and nonbeing, of negation and affirmation; this accords with the law of the unity and struggle of opposites. A leap includes the moment when the former phenomenon is replaced by the emerging one; the qualitative and quantitative changes mutually condition each other, in accordance with the law of the negation of the negation.

It is wrong to suppose that at first only quantitative changes occur, followed by solely qualitative changes, followed in turn by purely quantitative changes, and so on. In reality the transformation of one phenomenon into another involves interaction between qualitative and quantitative changes, which pass through a series of intermediate phases. Moreover, the various phases in the change of a given quality signify a change in the degree of that quality, making it in fact a quantitative change. “The intermediate links prove only that there are no leaps in nature precisely because nature is composed entirely of leaps” (F. Engels, in K. Marx and F. Engels, Soch., 2nd ed., vol. 20, p. 586). From the point of view of quantitative measurements, this transformation over time appears to be gradual, but from the point of view of qualitative measurements it is a leap.

The beginning of the leap from one phenomenon to another is marked by the beginning of a radical transformation of the entire system of connections between the elements of the whole —a transformation of the very nature of those elements. The completion of the leap signifies the unity of qualitatively new elements and the establishment of a different structure for the whole. Examples of great leaps in the development of objective reality include the formation of stars, especially the sun and its planets, the appearance of life on earth, the emergence of new species of plants and animals, the appearance of human beings and human consciousness, and the rise and succession of socioeconomic formations in human history. Revolution is a special form of leap typical of social development.

Two basic types of leaps may be distinguished in the process of development: a change at a single point in time, representing an abrupt transition from one quality to another; and a leap as a process continuing for some time. A leap may last a billionth of a second in processes on the microscopic level, billions of years in cosmic processes, or hundreds of thousands of years in the formation of animal species. The distinguishing characteristic of a leap is simply the emergence of a new quality marking the end of the previously operating law of quantitative changes. The first type of leap characteristically has clearly delineated boundaries in the transition, a very intense and speedy transition process, and a total restructuring of the entire system that seems to occur all at once. Examples of this kind of leap are atomic explosions and, in society, political revolutions.

If quality is taken to be a system of properties, it follows that isolated or partial leaps must be distinguished from general leaps. The former are connected with the appearance of new individual properties and the latter involve transformation of the entire system of properties—the quality as a whole.

Leaps may also be categorized according to the nature of the processes that are preliminary to the qualitative change. In one form of leap the transition boundary is very sharply delineated, as with the birth or death of an organism. The preliminary changes gradually grow to a certain limited magnitude without fundamentally changing quality. In leaps of another kind the process of radical transformation in quality is not preceded by gradual quantitative changes; the changes are part of the very process by which the system is restructured. Thus, the transfer of an electron from an outer orbital of an atom to an inner one fundamentally affects the chemical properties of the atom or molecule.

A change in quality also entails a change in quantity. In general form this is expressed in a pace of development that accelerates in proportion to the increase in the level of organization of matter.

The law of reciprocal transformation of quantitative into qualitative changes has great methodological importance. It obliges the investigator to study the object from both the qualitative and quantitative points of view taken together, so that quantitative descriptions do not overshadow the qualitative specificity of facts and laws. The law serves as a warning against all forms of flat evolutionism or reformism, as well as against the various types of catastrophism and, in social development, subjective adventurism.

Figure 1. (a) Circuit for the charging of a capacitor, (b) variation with time of the current in the charging circuit, (c) variation with time of the voltage across the capacitor plates; (E) emf, (I₀) initial current in the circuit, (S) switch, (Ft) limiting resistor, (C) capacitor, (i) charging current, (u) voltage across the capacitor plates, (t) time, (τ) charging time constant