In this lecture, Konstantinos Katsikopoulos presents the concept of bounded rationality and contrasts two - as he calls it - cultures of research and analysis within Behavioral Economics: an "idealistic" and a "pragmatic" approach. Thereby, Katsikopoulos discusses amongst others their different assumptions on decision making (utility optimization vs. achievement of a satisfactory outcome), the psychological process as well as the epistemic aim and implications on policy recommendations (nudging vs. education).