While most studies on attitudinal media effects are concerned with a comparable scientific question they do not always coincide in their theoretical approach. In the present paper, we show that this state of affairs has caused controversies about the meaning and testability of specific types of attitudinal media effects – in particular, framing, cultivation, priming, and persuasion effects. We argue that such disagreements are misguided and could be prevented by adopting four Principles as a meta-theoretical basis for all studies on attitudinal media effects. We show what these Principles imply for theory formulation, and we discuss how they relate to empirical falsification procedures.