77. The child on whom these experiments were made was obliged to express his sensations in the visual order, in a language which he did not understand. For any one who is deprived of one of the senses must be absolutely ignorant of all the ideas which have their origin in that sensation. Hence it follows that he knows nothing of the language relating to that sense, and the ideas which he joins to the words are entirely different from what those who possess that sense mean to express. The blind man will speak of colors and the impressions produced by sight, because he hears others speak of these things; but for him the word to see does not mean to see, light is not light, nor color color, as we understand them, but they express different ideas which he has formed according to the circumstances, in conformity with the explanations he has heard. What importance then should we attach to what a child may say who, besides the thoughtlessness natural to his age, is placed in a situation new to him, and required to express his ideas in a language which he does not know? He is asked, for example, if he can distinguish a greater object from another which is smaller, without considering that the words greater and smaller as he understood them, inasmuch as they expressed abstract ideas, or were referred to the sensations of touch, were altogether new to him when applied to objects seen, since he had no means of knowing what was meant when referred to a sensation which he experienced for the first time. If within a circle, a number of smaller circles of a different color were described, he would see the smaller circles within the circumference of the greater; but if asked if one appeared greater than the rest, or if he could distinguish the limits which, separated the smaller circles from each other, he could not but give very absurd answers, which the observers might perhaps take as the expression of curious phenomena. They speak to him of figures, lines, extremities, size, position, and distances in relation to sight, and as he is ignorant of this language, yet knows not that he is ignorant of it, he must necessarily talk in a very strange manner. A more attentive and profound observer would have perceived the same misunderstanding as when a deaf man disputes without hearing what was said.