The article presents a philosophic reflection on the concept of fault inprivate law. It is emphasized that while seeking for the substance of fault, one shouldbear in mind that the idea of fault liability is an indispensable implication of the verysubstance of law. Thus provisions of law are actual only for a free person. Freedom andthe law are like a condition and the conditioned effect. That is why the law imputes a faulton a person only for those offences that were freely committed i.e. given that a personhad a choice and exercised her autonomy of will. Hence fault constitutes a preconditionof legal liability because freedom constitutes a precondition of law. While ruling on thematter of fault court indeed ascertains if an offender was free in his commitment or notand if that commitment was an exhibition of personal autonomy.On that ground the author proposes to define fault as a juridical concept, thecontent of which consists in stating that the wrongful act was committed in situation offree choice, wherein the rightful variant of behavior was available and reasonablyexpected.