9 another issue that has been explored thoroughly - the State has better possibilities of assuming the function of proving what it denies, than the individual to prove what he affirms. Nevertheless, not even this frequently corroborated experience should lead to the adoption of an immovable rule: it is possible to accept the general effectiveness of the principle, while not accepting its universal applicability. Sergio García-Ramírez Judge Manuel E. Ventura-Robles Secretary