Lacking portability of therapeutic effects: the hierarchy of internal validity is insufficient-A response to Hans J. Trampisch.

evidence, and so forth. And then use clinical judgment, well-informed reasoning to draw conclusions. We have suggested one way how to do this, a matrix-analytical approach that looks at the full picture. This approach could be also structured, perhaps quantified and used along the lines of a Bayesian kind of reasoning. Such a view makes the life for institutions like the one headed by Prof. Windeler very complicated, I know, because they have to use argument, clinical judgment, and consensus instead of cook-book algorithms to make decisions. But I am sorry if reality is more complicated than we would have it. I feel: we have an obligation to honor reality, not our ideas about reality.