By extension blind [man] would mean either the perception caused in his touch by something he calls extended, or else the power of raising that perception; wch power is without, in the thing termed extended. Now he could not know either of these to be in things visible till he had try'd.
Geometry seems to have for its object tangible extension, figures, & motion—and not visible[212].
A man will say a body will seem as big as before, tho' the visible idea it yields be less than wt it was; therefore the bigness or tangible extension of the body is different from the visible extension.
Extension or space no simple idea—length, breadth, & solidity being three several ideas.
Depth or solidity now perceived by sight[213].
Strange impotence of men. Man without God wretcheder than a stone or tree; he having onely the power to be miserable by his unperformed wills, these having no power at all[214].
Length perceivable by hearing—length & breadth by sight—length, breadth, & depth by touch.