  Early criticisms of Landauer's principle tended to focus on the claim that logically reversible operations could be implemented in a thermodynamically reversible fashion, and instead to defend the position of von Neumann, Gabor and Brillouin (see the references in Landauer's response (Porod 1988) and in (Bennett 2003) for examples of this debate). The increasingly explicit models developed by workers such as Bennett, Fredkin and Toffoli have now generally been considered to have established that thermodynamically reversible computation is indeed possible, if implemented by logically reversible computers.