4. To make them signify the absence of positive ideas.
Besides these names which stand for ideas, there be other
words which men make use of, not to signify any idea, but the want or absence of some ideas, simple or complex,
or all ideas together; such as are nihil in Latin, and in English, ignorance and barrenness. All which negative or
privative words cannot be said properly to belong to, or signify no ideas: for then they would be perfectly
insignificant sounds; but they relate to positive ideas, and signify their absence.