96.  To set this matter in a clearer light I shall make use of an example.  Suppose the above-mentioned blind person by his touch perceives a man to stand erect.  Let us inquire into the manner of this.  By the application of his hand to the several parts of a human body he had perceived different tangible ideas, which being collected into sundry complex ones, have distinct names annexed to them.  Thus one combination of a certain tangible figure, bulk, and consistency of parts is called the head, another the hand, a third the foot, and so of the rest:  all which complex ideas could, in his understanding, be made up only of ideas perceivable by touch.  He had also by his touch obtained an idea of earth or ground, towards which he perceives the parts of his body to have a natural tendency.  Now, by erect nothing more being meant than that perpendicular position of a man wherein his feet are nearest to the earth, if the blind person by moving his hand over the parts of the man who stands before him perceives the tangible ideas that compose the head to be farthest from, and those that compose the feet to be nearest to, that other combination of tangible ideas which he calls earth, he will denominate that man erect.  But if we suppose him on a sudden to receive his sight, and that he behold a man standing before him, it is evident in that case he would neither judge the man he sees to be erect nor inverted; for he never having known those terms applied to any other save tangible things, or which existed in the space without him, and what he sees neither being tangible nor perceived as existing without, he could not know that in propriety of language they were applicable to it.

97.  Afterwards, when upon turning his head or eyes up and down to the right and left he shall observe the visible objects to change, and shall also attain to know that they are called by the same names, and connected with the objects perceived by touch; then indeed he will come to speak of them and their situation, in the same terms that he has been used to apply to tangible things; and those that he perceives by turning up his eyes he will call upper, and those that by turning down his eyes he will call lower.

98.  And this seems to me the true reason why he should think those objects uppermost that are painted on the lower part of his eye:  for by turning the eye up they shall be distinctly seen; as likewise those that are painted on the highest part of the eye shall be distinctly seen by turning the eye down, and are for that reason esteemed lowest; for we have shown that to the immediate objects of sight considered in themselves, he would not attribute the terms high and low.  It must therefore be on account of some circumstances which are observed to attend them:  and these, it is plain, are the actions of turning the eye up and down, which suggest a very obvious reason why the mind should denominate the objects of sight accordingly high or low.  And