  Landauer did not, in his 1961 paper, directly address the question of whether a measurement was logically reversible or irreversible, but only questioned whether the concept of a measurement had been defined sufficiently well in the work of Brillouin and others. At that point in time, he regarded logical irreversibility as an essential part of computation and believed this was responsible for a necessary minimum heat generation in information processing. His arguments were presented as making more precise the arguments of Brillouin and von Neumann.