8 32. The idea of “presumption of innocence” –or better, perhaps, of a “principle of innocence or non-guilt,” for the benefit of those who object to the “presumptive” nature of this concept- has existed for two hazardous centuries. One could hardly find a principle that is more consistent with democratic criminal justice, which entrusts the State as accuser with proving the allegations and the State as judge with deciding on them. Our American Convention embodies the principle: “Every person accused of a criminal offense has the right to be presumed innocent so long as his guilt has not been proven according to law” (Article 8(2)). The Inter-American Court has also stated in its November 12, 1987 judgment on the Suárez Rosero case, and reiterates it in the judgment on the instant case, that the principle of presumption of innocence is the foundation for the right to fair trial. The latter is, in fact, built around the idea of innocence, which does not block criminal prosecution, but rationalizes and channels it. Historical experience supports this approach. 33. This principle is in the heading of the provisions on defendants, in the 1955 Standard Minimum Rules for the Treatment of Prisoners: “Unconvicted prisoners are presumed to be innocent and shall be treated as such” (rule 84.2). And principle 36 of the body of provisions for the protection of all persons under any form of detention or imprisonment, in 1988, sets forth: “A detained person suspected of or charged with a criminal offence shall be presumed innocent and shall be treated as such until proved guilty according to law in a public trial at which he has had all the guarantees necessary for his defence.” 34. Of course, I am aware of the obstacles to full application of this presumption or principle. They are, undoubtedly, the often debated precautionary measures in the criminal proceeding, first and foremost preventive incarceration, to which there have always been objections. Another obstacle is the very fact that the criminal procedure is based on the opposite idea: reasonable evidence of criminality, probable criminal liability, the existence of data that provide grounds to believe that a given individual participated in a specific criminal act, and so forth. 35. Nevertheless, this presumption or this principle is an extremely valuable reference for the construction of the proceeding, to address doubts that may arise during the proceeding, to recover guarantees and to reduce disproportionate interference. The nature and outcome of the procedural acts and of the proceeding as a whole are very different when the defendant is treated “as if he were guilty,” which is a trait of the inquisitorial system, and when he is treated “as if he were innocent,” which is a trait of the accusatory one. Ultimately, what the presumption or principle of innocence seeks is to exclude prejudice –advanced, general and condemnatory judgment against the defendant, without being based on the evidence of the facts and of the liability- and to avoid advanced punishment based on vague appearances. VIII. Arbitrary detention 36. The case that this Opinion refers to shows, once again, the great flaw at the outset of the proceeding, or at least the one that most often and overwhelmingly victimizes the defendant –the one “presumed innocent”- and weighs on the rest of the data of the prosecution by the State: arbitrary detention. It is not easy, now, to find legal standards that do not address the lawfulness of this very significant, delicate, and devastating measure. Efforts have been made to surround it with conditions: that detention must be based on the law, that it must be conducted by a competent authority, that it must be ordered by a judicial authority, that it must be recorded in writing, that the detainee must be presented. This catalogue of good intent, duly