Throughout this essay, I will consider an argument frequently used to justify paternalistic behavior toward a specific class of persons: illiterate people. The argument states that illiterate people are uneducated, lack information and understanding, and are thus unable to make decisions. Therefore, it is argued, paternalism in their case is justified. The conclusion is that illiterate persons cannot be autonomous. The justification for this view is based on an a priori attitude: since it is impossible to communicate, physicians should decide which kind of treatment the illiterate patient should receive. This argument is frequently used even though its proponents may not be aware of its implications. Given the importance and uncritical acceptance this argument has in Argentina, and also in other Latin American countries, I think it is relevant to analyze carefully what it means. I propose a thorough analysis of this argument, of its implications and an evaluation of whether it is acceptable.