 There is, however, a second family of principles which do appear directly to conflict with Occam’s Razor. These are so-called ‘principles of plenitude.’ Perhaps the best-known version is associated with Leibniz, according to whom God created the best of all possible worlds with the greatest number of possible entities. More generally, a principle of plenitude claims that if it is possible for an object to exist then that object actually exists. Principles of plenitude conflict with Occam’s Razor over the existence of physically possible but explanatorily idle objects. Our best current theories presumably do not rule out the existence of unicorns, but nor do they provide any support for their existence. According to Occam’s Razor we ought not to postulate the existence of unicorns. According to a principle of plenitude we ought to postulate their existence.