 This criticism of any metaphysical claims concerning the ultimate constitution of reality is accompanied by a more general warning against the overstepping of the natural limits of our cognitive faculties. According to Locke it is just a fact about human nature that there are limits to the powers of the understanding. These powers are meant to be bestowed to us by God to an extent sufficient for us to know “Whatever is necessary for the Conveniences of Life, and Information of Virtue” (Essay I.I.5; see also II.XXIII.12) but only to that extent. If therefore the nature and the constitution of substances both corporeal and spiritual are beyond our cognitive grasp then we should take this to be a hint that God has set limits to what we can know because he sees no reason for us to know everything. Even if the powers He endowed on us would be magnified infinitely we still would remain clueless as to what substances really are because we still would be stuck in a world of qualities (this is one way of reading Essay II.XXIII.12). Thus, in the end metaphysical knowledge of any kind is meant to be beyond our reach. This, however, is nothing we should be concerned about: