6.3.5 Why is the Aristotelian formula unfeasible?

At first glance, the Aristotelian formula offers a better way (than the CJEU-definition) of addressing the question whether the differences between the bank State aid cases justify the differences in treatment. Indeed, the Aristotelian principle requires not only that unlike cases are treated unalike; they should be treated unalike, proportionate to the differences between them. From this perspective, it is not enough to simply establish that cases are different, it should also be established how different the cases are. The treatment should be correspondingly different. So this raises the question as to the comparability of the cases and the comparability of the treatments.

The comparability (or the degree to which cases are different) is a rather vague concept if it is not defined in what respect the cases are different. In my opinion, there are essentially two approaches. State aid cases are characterised by many different characteristics. One can either compare the cases on the basis of all those different characteristics, or one can combine all those characteristics into one single metric1 and compare the cases on the basis of this metric. So there are two approaches, which I have labelled in this PhD-study as the ‘one- metric approach’ and the ‘many-variables approach’. However, both approaches are problematic. This will be explained in sections 6.4 and 6.5.