Thomas Walter Laqueur (born September 6, 1945) is an American historian, sexologist and writer.

He is the winner of the Andrew W. Mellon Foundation's 2007 Distinguished Achievement Award,[2] and is currently the Helen Fawcett Distinguished Professor of History at the University of California, Berkeley, located in Berkeley, California.

[3] Laqueur wrote that there was an ancient "one-sex model", in which the woman was only described as imperfect man / human and he postulates that definitions of sex/gender were historically different and changeable.

[4] This argument has been challenged by some historians of science, notably Katharine Park and Robert A. Nye;[5] Monica Green,[6] Heinz-Jürgen Voss,[7] and Helen King,[8] who reject the suggestion that ancient descriptions show a homogenous model, the one-sex model which then mutated in the 18th century to a two-sex model.

They encourage a more differentiated perception that makes clear that gender theories of natural philosophy as well as biology and medicine, are embedded and constructed in certain social contexts.