Abstract
Since the beginning of the twentieth century, the principle of individualization of punishment has enjoyed a growing reputation. The time when sentences were set according to the seriousness of the crime alone is over. It is now accepted that it must also be adapted to the personality as well as the situation of the offender. Nevertheless, the reality of the place occupied by the principle of individualization of the sentence within French criminal law raises questions. Initially enshrined in law, the principle then acquired constitutional value. It has thus gradually spread to new measures thanks to the combined action of the legislature and the Constitutional Council. In spite of the importance given to the principle, its affirmation remains ambivalent in view of the many limits that persist and that are still created in the service of successive and contradictory penal policies.The implementation of the principle obeys this same paradox. While the tools for individualizing the sentence are multiplying, they are so complex that the judge is no longer able to use them properly. Added to these difficulties is the lack of information about the accused. The trial court is forced to regularly use the same sentences from the repressive arsenal, delegating the mission of individualization to the sentence enforcement court. With the benefit of greater hindsight, the sentence enforcement judge sees his or her competences developed in order to ensure a late adaptation of the sentence. If the recent generalization of the motivation of the sentence could have served the purpose of individualization, it is still too uncertain to ensure the effectiveness of the principle.