 Much mathematical activity is driven by factors other than justificatory aims such as establishing the truth of a mathematical fact. In many cases knowledge that something is the case will be considered unsatisfactory and this will lead mathematicians to probe the situation further to look for better explanations of the facts (see Atiyah’s vivid account of an instance of this in Minio 1996, 17). This might take the form of, just to give a few examples, providing alternative proofs for known results, giving an account for surprising analogies, or recasting an entire area of mathematics on a new basis in the pursuit of a more satisfactory ‘explanatory’ account of the area. The phenomenology of the variety of such explanatory activities has been partially investigated in Sandborg (1997, ch. 1) and Hafner &amp; Mancosu 2005 (see also Robinson 2000 for a cognitive analysis of proof emphasizing explanatory factors, Lange 2017 for further examples, and Colyvan 2012b for a textbook presentation).