Meditation is an exercise, coming in several styles, of directing attention in a special way to a person’s direct awareness, while restricting input and output of the body-mind system. It is claimed (by the meditation tradition and by many practitioners) that doing this is beneficial in several ways: temporary states of diminished stress and even permanent liberation in several degrees from causes of suffering. Also it is claimed that mentioned benifits are wholesome: they may lead to more inner peace for the practitioner involved, but also more harmony for the environment of this person. Finally, it is even claimed that the method gives fruitful hints for cognitive neuroscience and clinical psychology. The putative fruits of the practice (similarly to those of studying, say, physics, a new language, or a musical instrument) only appear when a sufficient amount of discipline and effort is applied and when the practitioner has intention towards and affinity with the method. Therefore, it is methodologically not clear how to assess the aforementioned claims. The discussion will be about this fundamental problem of evaluating the highly promising discipline of meditation.