Autopoiesis is just one of several current theories of life, including the chemoton[20] of Tibor Gánti, the hypercycle of Manfred Eigen and Peter Schuster,[21] [22] [23] the (M,R) systems[24][25] of Robert Rosen, and the autocatalytic sets[26] of Stuart Kauffman, similar to an earlier proposal by Freeman Dyson.[27] All of these (including autopoiesis) found their original inspiration in Erwin Schrödinger's book What is Life?[28] but at first they appear to have little in common with one another, largely because the authors did not communicate with one another, and none of them made any reference in their principal publications to any of the other theories.