We discuss how to aggregate multiple criteria evaluations belonging to qualitative, linearly ordered scales. Qualitative aggregation operations such as min or max can be refined by discrimin and leximin orderings, in agreement with the Pareto ordering of vector evaluations. Further refinements of discrimin orderings, as well as the generalization of discrimin and lexirnin to functions other than min or max, are presented. Lastly, it is pointed out that a generalized leximin is not sufficient for describing any aggregation structure. However, the definition of aggregation structures in qualitative scales amounts, in practice, to the specification of a small number of positionings of aggregation results.