You can make a chair intelligible by touching, by looking at it, and seeing how it is made. You make a house intelligible by seeing how it is made. You can make a tree intelligible by seeing how it is: its stem, fruits, leaves, appearance, then what comes out of it. The word intelligible means through our senses we feel a thing, we know a thing, we have a conception of a thing; that is to make it intelligible. To make anything intelligible is to make a concrete conception of it.