We have all of us always believed in the veritable existence of this outside world from our childhood. So have we believed always in our own real and continued personal existence. The unyielding objectivities concerning which our senses inform us--the identical Self which receives their information--are entities no man ordinarily thinks of calling in question. Let any one sit down and try to imagine himself a human animal let loose upon life without a firm belief in either of these two primary convictions. What could life be to him? to his descendants? to the world of men if similarly unbelieving? Yet what are the conditions or evidences of veracity upon which his and his fellows' present convictions must necessarily repose? Can he and others help believing them true? and why?--This "why" is a safe answer to the most plausible as well as the most refined objection against such primary beliefs as those premised by Natural Theology. [102] Cheselden's case is reported in the Philosophical Transactions for 1728, and also in his Anatomy. Respecting the point above quoted he is confirmed by Mr. Nunneley, "_On the Organs of Vision_," 1858. [103] See Dr. Carpenter's Principles of Human Physiology. Ed. 7. p. 713. § 635. [x] The following quaint apology for our senses at the expense of our understanding may be new to the majority of my readers:-- "We have seen two notorious instances of _sensitive deception_, which justifie the charge of _Petron. Arbiter_. Fallunt nos oculi, vagique sensus Oppressâ ratione mentiuntur.