The central question is whether the form of explanation in history is typically the same as that of the natural sciences. Principal proponents of the claim that there is no essential difference included the logical positivists, for whom all legitimate explanation would conform to the pattern they believed to be exhibited in natural science. The opposing view stresses the differences characteristic of historical enquiry. These include the fact that historical events are particular, dated, and unrepeated complexes of human interaction, unlike the repeatable events of science (see idiographic/nomothetic methods). They also depend upon human intention and motivation, although different schools of historians have seen individual human endeavours as more or less important to particular social and political explananda. There is also the residual question of whether explanation by motivation and intention is itself of the same form as scientific explanation (see functionalism, simulation, Verstehen). The most celebrated proponents of the distinctive nature of historical explanation are Dilthey and Collingwood.