The term "Constructivism" was invented c.1914 by Russian artist Vladimir Tatlin to define objects built rather than cast or carved, or any design in two or three dimensions reminiscent of Euclid: flat and rectilinear or made with straight edge or compass.
The constructivists (1913-1922) include some of my favorite Russian artists: Tatlin, Malevich, Rodchenko, El Lissitzky, Naum Gabo, Antoine Pevsner and (briefly) Wassily Kandinsky.
In the preface to the revised edition, the author presents this list of visual verities ". . . waiting like the keys of a piano for a human touch:"