Comparing legal systems involves, at least to some degree, exploring both similarities and differences. For some writers, this forms part of the definition of comparative law. Some comparative lawyers have generally emphasized differences, while others see similarities, particularly in problems and their results, and a third group has sought to strike a balance between observing and analysing similarities and differences. Drawing on a debate in comparative history, this article argues that the proper balance between looking for similarities and for differences depends on the purpose of the comparative enquiry. Furthermore, it links the issue of difference or similarity to the various steps which are involved in a comparative legal enquiry, suggesting that some steps require more focus on similarity, others on difference, and many call for a balance of both.