We live in an amazing universe. Why the universe does exist? Why does anything at all exist? Gottfried Leibniz wrote, “The first question which should rightly be asked is: Why is there something rather than nothing?” He concluded that he found the explanation in God. However, is this reasonable? Everything that exists has an explanation of its existence. If the universe has an explanation of its existence, that explanation is God. The universe exists. From these it follows logically that the explanation of the universe’s existence is God. The logic of this argument is airtight. If the three premises are true, the conclusion is unavoidable. However, are these premises more plausibly true than false? The third premise is undeniable for anyone seeking truth. However, what about the first premise? Why not say, “The universe is just there.” No explanation needed! End of discussion! Imagine we are hiking in the woods and come across a shiny sphere lying on the ground. We would naturally wonder how it came to be there. In addition, we would think it is odd if someone said, “There is no reason or explanation for it. Stop wondering. It just IS!” In addition, if the ball were larger it would still require an explanation. In fact, if the ball were the size of the universe, the change in its size would not remove the need for an explanation. Actually, curiosity about the existence of the universe seems scientific and naturally intuitive.
Atheists might say “If everything that exists needs an explanation, what about God? They argue that God needs an explanation also. In addition, if God does not need an explanation, then why does the universe need an explanation? To address this, Leibniz makes a key distinction between things that exist NECESSARILY and things that exist CONTINGENTLY. Things that exist NECESSARILY exist by necessity of their own nature. It is impossible for them NOT to exist. Many mathematicians think that abstract objects like numbers exist like this. Something does not cause numbers to exist; they just exist by necessity of their own nature.
For many rational people, something causes things to exist CONTINGENTLY. Most of the things we are familiar with exist contingently. They do not HAVE to exist. They only exist because something else caused them to exist. If our parents had never met, we would not exist! There is no reason to think the world around us HAD to exist. If the universe had developed differently, there might have been no stars or planets. It is logically possible that the whole universe will not have existed. It does not exist necessarily because it exists contingently. If the universe might NOT have existed, why DOES it exist? The only adequate explanation for the existence of a contingent universe is that its existence rests on a non-contingent being, which is something that exists because of the necessity of its own nature. It would exist no matter what!
Therefore, “Everything that exists has an explanation of its existence”…”either in the necessity of its own nature, or in an external cause.” However, what about our second premise? Is it reasonable to call the explanation of the universe…God? Well, what is the universe? It is all of space-time reality, including all matter and energy. It follows that if the universe has a cause of its existence, that cause cannot be part of the universe – it must be non-physical and immaterial – beyond space and time. The list of entities that could possibl
PRIMARY SOURCES: Dr. William Lane Craig Videos on Leibniz’ Contingency Argument.