In political philosophy, there has been an ongoing discussion about the relevance of abstract theorising which results in the elucidation ‘ideal principles of justice’. It might be argued that such a project is worthwhile because philosophy need not be action guiding, or instead that it is for philosophers to consider questions of values and for the social scientists to work out whether the most normatively defensible proposals are feasible. Opponents of such a project have argued that such theories cannot be sufficiently action-guiding or motivating, or are worthless unless they can be implemented. Instead, it is suggested, considerations of feasibility should guide our normative theorising. The subject of climate justice provides a most apt case study for this debate. Issues of feasibility have been an integral part of the political discussions: from the capacity for technological and social change to economic and political feasibility. Any party’s claim to invoke feasibility can, and often is, countered with the charge that they are using it to justify the status quo. Which, then, are genuine feasibility constraints and which are not? This paper outlines a typology of proposed feasibility constraints, using those encountered in discussions of climate change as an example. Some are generated by deliberate human-decision making. For some these, there is a problem in that they are implicitly reliant on normative considerations. This blurs the supposed distinction between normative theorising and questions of feasibility. Other proposed constraints might be thought of as being generated due to unfortunate circumstances, such as laws of nature, or epistemic difficulties. If this is the case, then what counts as feasible is of course subject to change – but few discussions of feasibility constraints appear to acknowledge this. The paper concludes some reflections on what can count as genuine feasibility constraints in the case of climate change.
