We introduce description logics as a means to carry out sentiment inferences triggered by some verbs on their semantic roles. Verbs might impose polar effects on some roles, but also have polar expectations on other roles. For instance, an entity inherits a positive polarity just by being actor of some verb ("she succeeds"). More complicated scenarios arise if we take subclause embeddings, negation and polarity conflicts into consideration. Polarity propagation and effect inversion need to be coped with, then. We have implemented a prototype in OWL covering a substantial subset of our verb lexicon covering about 140 German verbs.