Human flourishing is the topic of an increasing number of books and articles in educational philosophy. Flourishing should be regarded as an ideal aim of education. If this is defended, the first step should be to elucidate what is meant by flourishing, and what exactly the concept entails. Listing formal criteria can facilitate reflection on the ideal of flourishing as an aim of education. We took Aristotelian "eudaimonia" as a prototype to construct two criteria for the concept of human flourishing: (1) human flourishing is regarded as intrinsically worthwhile and (2) flourishing means "actualisation of human potential". The second criterion has three sub-criteria: (2a) flourishing is about a whole life, (2b) it is a "dynamic state" and (2c) flourishing presupposes there being objective goods.