The four polar years are used as windows for highlighting changes in the character of polar research over the past 125 years. The approach taken may be seen as one of an archaeology of knowledge. As such it fixes on four separate strata in the history of science and seeks to lay bare distinctive features in each of these. To simplify, the focus is selective, mainly presenting three types of aspect for each year. The first is the character of the instruments and research technologies employed in each, and the second is the kinds of problems tackled, while the third is the associated view or ideal of science that stands out. The latter aspect has to do with epistemology. The paper suggests that whereas work during the first International Polar Year (IPY) reflected an empirical inductivist philosophy of science, during the second IPY a mix of problem oriented, and hypothesis driven, approaches existed alongside inductivism. By the time of the International Geophysical Year (IGY) the theoretical foundations of polar research had grown stronger and much of the focus had shifted to larger scale geophysical processes. Finally, today's ambition to develop an integrated Earth system science reflects an ideal that is systemic, constructivist and predictive. Such epistemological features are evident in some of the most advanced forms of computer aided analysis of Arctic and Antarctic processes, as well as in visualisation methodologies used to interpret and present data, concepts, models and theories. This latest approach is evident in some of the planning and agenda setting documents generated under the auspices of the current IPY.