Prof. Lyra discusses in this article the basic problem of criminological sciences, stating that its essential object of study is the determination of the genesis of crime. The Author states that, before defining the crime genesis, it is necessary to outline, through a synthesis of epistemological restructurization of criminology itself. This way, we can develop a conception of Dialectic Criminology, where the term "dialectic" does not necessarily coincide with a marxist posture, but it extends along much more complex and comprehensive parameters. Dialectic Criminology is defined, in Lyra's conception, as a Classified Criminology, synthetizing both the psychological approach (clinical criminology, or micro-criminology), and the sociological approach (sociological criminology or macro-criminology), according to an anthropological basic frame of reference, which constitutes the new and original prerequisite. To this aim, according to Prof. Lyra, it is necessary to overcome merely biological or psychological theories, and the new sociologisms, which cannot explain deviant behavior without falling into dogmatism or relativism. It is necessary to give back to criminology its original ethico-philosophical roots, and to place the problem of crime within a new "praxis" concept, which takes into account the authentic freedom of man, interracting with historical evolution. This way, through Dialectic Criminology, we can overcome the conception of crime and delinquency viewed as counterparts of the concept of Law.