The principle of sufficient reason in practical terms means that there is a reason for why things occur or exist. The principle of sufficient reason has been formulated as follows:
- For any contingent entity, there is sufficient explanation for why it exists.
- For everything that exists, there is a reason for its existence, either due to the casual efficacy of other beings or due to the necessity of its own natures.
- By sufficient reason in the full sense I mean an explanation adequate for the existence of some particular being. An adequate explanation must ultimately be a total explanation, to which nothing further can be added.
Douglas Groothuis in his Christian Apologetics: A Comprehensive Case for Biblical Faith believes that this principle offers help for the cosmological argument because the universe is not self-explanatory. If the universe is not self-explanatory, it is contingent. It, like all other things within the universe, has a beginning. The cosmological argument argues for the existence of God based upon the cause and effect nature of things. If there is sufficient reason for the universe, God is the best candidate to be that very reason.
Groothuis champions the idea that only the explanation for the universe that appeals to God is satisfactory because the option of denying it would lead to some very unfortunate ends. If the principle of sufficient reason were rejected, the author believes it would mean the universe is meaningless. Total meaninglessness entails nihilism which is both unlivable and counter-intuitive to our morals and very existence. Humanity then lacks objective worth and dignity. The disasters and moral atrocities of such a viewpoint would be limitless if it were to be lived out. Furthermore, it makes arbitrary and ad hoc to search for explanations concerning others things within our world (the endeavor of science). Groothuis also rejects the idea that the universe is self-existent, it is a thing that explains itself. He points out that we find nothing within our universe that would lead us to believe the universe exists by its own nature. Humanity has no problem looking for the cause of things within the universe or wondering if those certain things should have never existed in the first place. How much more the universe itself?