This is achieved by providing a detailed account of the origins, writers, and legal concepts behind Crimes against Humanity, while also drawing attention to important ideologies. The analysis revealed that the prohibition on Crimes against Humanity stems from a liberal worldview, especially regarding its founder; yet, subsequent jurisprudence has shown a limited influence of liberalism. The paper found that there has been no uniform assessment of mens rea across various courts. Concerning the notion of constructive knowledge and the significance of determining purpose, opinions differ. The minimum level has been characterized as recklessness, however the baseline in case law might vary depending on the evaluation. This is very improbable in light of the present mens rea requirement under ICC law; the more practical standard is indirect purpose.