The article examines how to apply moral and philosophical reflection in the commission of a crime. An action is the result of solving an equation with many variables. This is overcoming legal, moral, philosophical, and emotional contradictions. However, modern legal and ethical thought closes the way for understanding its causes and motives. As an example, we examine the conspiracy and murder of Caesar in Rome in 44 BC. The article reveals objective differences in the understanding of morality in antiquity and in modern ethical science. Here we analyze the philosophical and ethical grounds that will help solve this dilemma. First of all, we considered the philosophical and political works and letters of Cicero. His reasoning about the duties of a citizen might have influenced Brutus' decision to participate in the conspiracy against Caesar and accept the moral choice as his fate. Brutus did not act as a murderer, but as an exponent of public purpose and public utility, for whom the purpose of the act was the public good, incompatible with tyranny.