People who are deaf and have sign language as their native language at their command, move parts of the body, especially their hands, in order to visualize their thoughts in images and thereby convey them to others. Their language essentially consists in visualization through movements. It could therefore be considered a sort of pictorial language. But the word ‘pictorial' ought to be understood in a radical sense. For the deaf people, as far as we have been able to find out in our research, fundamentally think in pictorial entities, that is, they originally form their thoughts on the basis of visual impressions of the world. Here is the possibility that their thoughts are genuinely corresponding to the world that they perceive visually. It is therefore important to understand precisely how the people who have a good command of the pictorial language recognize the world and think about it. Such an understanding could contribute to the epistemological and ontological research on the correspondence between thought and its perceptive object. For this purpose, we have tried to provide a clear description. Our argument was called into question, however, by Prof. SASAKI Noriko. She mentions the following four questions in short: 1. Are the thoughts of the deaf people indeed of a pictorial nature? 2. Do not people without hearing impairment think in pictorial forms as well, equal to the deaf people? 3.Is sign language indeed based on pictorial thinking? 4. Does a perfect correspondence of thought and perceived world not also exist in spoken language? We respond to these questions and we try to clarify how the deaf people think about the perceived world once again, from a new point of view, namely in perspective of "the problem of fact (quid facti)" and "the problem of right (quid juris)" (according to Kant) concerning the correspondence between thoughts and the world.