Russian avant-garde movement pioneered in c.1914 by the artist Vladimir Tatlin and current until c.1921.
Following the examples of collage in cubism and futurism, Tatlin proposed a 'culture of materials' in which illusionism and simulated effects in art were eschewed in favor of an art based on the construction of real materials.
After 1917, artistic links with industry were emphasized together with the development of a non-objective 'production art' for the improvement of society.
Outside the USSR, the Russian brothers Naum Gabo and ANTOINE PEVSNER (1886-1962) pursued a less austere interpretation of the movement, as set out in their Realistic Manifesto (1920).
A view in the philosophy of mathematics which insists that mathematical entities (numbers, sets, proofs, and so on) can only be said to exist if they can be constructed; that is if some method can be specified for arriving at them on the basis of things we accept already.
One advantage of this is that various paradoxes can be excluded before they arise. A disadvantage may be that certain things are excluded that appear to be intuitively acceptable.
Also see:· constitutive variable