3. Impossibility and Identity not innate ideas
"It is impossible for the same thing to be, and not to be," is certainly (if there be any such) an innate PRINCIPLE. But can any one think, or will any one say, that "impossibility" and "identity" are two innate IDEAS? Are they such as all mankind have, and bring into the world with them? And are they those which are the first in children, and antecedent to all acquired ones? If they are innate, they must needs be so. Hath a child an idea of impossibility and identity, before it has of white or black, sweet or bitter? And is it from the knowledge of this principle that it concludes,that wormwood rubbed on the nipple hath not the same taste that it used to receive from thence? Is it the actual knowledge of IMPOSSIBILE EST IDEM ESSE, ET NON ESSE, that makes a child distinguish between its mother and a stranger; or that makes it fond of the one and flee the other? Or does the mind regulate itself and its assent by ideas that it never yet had? Or the understanding draw conclusions from principles which it never yet knew or understood? The names IMPOSSIBILITY and IDENTITY stand for two ideas, so far from being innate, or born with us,that I think it requires great care and attention to form them right in our understandings. They are so far from being brought into the world with us, so remote from the thoughts of infancy and childhood, that I believe,upon examination it will be found that many grown men want them.