One can only attribute this contention to aesthetics or faith. Both of which are contingent. I would think from a scientific perspective we would have to make the difficult admission that neither our being or our particular efforts are in any integral way a historical necessity in the geological and cosmological history of a planet that has witnessed far greater catastrophes than those of which we have the current capacity. In a longer period, we can be almost certain from the science in which we have banked our certainty that the greatest catastrophe is the inevitable inferno under which this garden will boil under the heat of the growing sun only to be swallowed by it after having been thoroughly broiled. That we are our own custodians to the best of our ability is most certainly a reasonable imposition to place upon ourselves as a whole. But, we cannot deny that the task of protecting the state of our earth in some form that we have come to consider normative for our own purposes, is one that we cannot even conceive of having the power to accomplish.