The thesis is dedicated to the question of how legal culture affects the perception of morality in patent law regimes and whether a better understanding of the terms can ease their complex relationship. To this end, the role of moral considerations in European, German, US and Chinese patent law is analyzed. The analysis shows the unique and paradoxical relationship between immorality and illegality in patent law compared to other areas of law. Furthermore, it is found that the interpretation of the fundamental function of patent law significantly influences the understanding of morality in patent law. Therefore, a moral standard in patent law cannot be identified universally across different patent law systems. Consequently, (legal) cultural aspects must always be included in the interpretation of patent law. Ultimately, aspects of legal culture and societal interests can be balanced in a proportionality approach.