The other kind of human knowledge is that of intelligible things; that is, it consists of intelligible realities which have no outward form or place and which are not sensible. For example, the power of the mind is not sensible, nor are any of the human attributes: These are intelligible realities. Love, likewise, is an intelligible and not a sensible reality. For the ear does not hear these realities, the eye does not see them, the smell does not sense them, the taste does not detect them, the touch does not perceive them. Even the ether, the forces of which are said in natural philosophy to be heat, light, electricity, and magnetism, is an intelligible and not a sensible reality. Likewise, nature itself is an intelligible and not a sensible reality; the human spirit is an intelligible and not a sensible reality (16:3)

End of Quote