Mind is an onion to which reason is but a skin. Our rational and irrational aspects make out real motives suspect. Take the case of Socrates. He is accused of impiety and is condemned to death. Real reason was something else. Take the case of Uriah whom David, the King of Israel had killed. Official version was that he was killed in action. The truth of the case hinged on his adultery with his wife Bathsheba. But by the spirit of the Lord his crime was revealed to him. In the manner we explain ourselves to the world, the public persona and our motives lie different shades of meaning. My use of onion as an analogy is (to) illustrate this complex aspect of mind. Mind is not any part of human anatomy but a world in which certain interlocking arrangement exists between internal thinking process and external stimuli.Add to this electro-chemical impulses on which neural information rides.
Why are we keen to explain ourselves when we are not obliged to give account? Human beings of all the beings on this planet are Homo sapiens, the wise ones. We feel in the fitness of things where it is only our thoughts and the reasonableness of these can put us at ease. But is it the only way we can feel as part of our home planet? How dogs or birds make sense of the world is altogether different. Snakes have sets of sensors beneath their jaws and create an infrared picture of their environment. Their movement and hunting habits are quite different from other species. It is no less adequate or less real. Be that as it may Earth and the universe can be counted meaningful to us only when we understand them rationally.
We will then have to admit that if we think up one universe, a multiverse also is quite possible. Whether one or many what it boils down to is this: man as with other species must account for nature. There is only one nature possible in which rational mind of man is coordinating with nature of the externals– Nature to designate as distinct from his own, to get the best out of that particular transaction. Every species will have its special needs and peculiar ways these may be satisfied.
Nature of universe as perceived by human beings is internalized, where reason is only a tool to give standpoint of each its appropriateness. According to Leibniz the German philosopher, the actual world was the best of all possible worlds, which he arrived at in his attempt to explain the nature of God. He viewed God as Omnipotent God. From that standpoint he stated God was good. Voltaire the skeptic on the other hand ridiculed the notion. For the Frenchman whose optimism was lost in the Lisbon earthquake in which some 100,000 people, innocents and bad alike had perished, viewed God differently. For the French skeptic his nature was to be explained from the effect. Here you see reason when explained from two standpoints cannot agree. The German explained the nature of the world from Cause while Voltaire chose to explain the nature from the effects. Reason may approach the nature of the world from a particular standpoint. In short reason may suit the nature of human beings to explain Nature and if other species employ other means they are not less served. The universe is unknowable in all parts yet nature of a life form interfacing with Nature is its own reward.