If an object is of whatever character I or any man or men will have it to be or imagine it, it is a fiction; but if its characters are independent of what you or I or any number of men think about it, it is a reality. The object of that final settled opinion to which it is supposed that an investigation will lead, if carried far enough, satisfies this definition of reality; for though the perversity of generations of men may postpone the agreement indefinitely, yet it cannot alter the character of the belief which alone can be permanently established.
http://www.commens.org/dictionary/entry/quote-chapter-iv-reality-0