: We in fact have sensation of everything of which touch can give us sensation (for all the qualities of the tangible qua tangible are perceived by us through touch); and absence of a sense necessarily involves absence of a sense organ; and all objects that we perceive by immediate contact with them are perceptible by touch, which sense we actually possess, while all objects that we perceive through media, ie without immediate contact, are perceptible by or through the simple elements, eg air and water.