THE 300th anniversary of the death of the polymath Gottfried Wilhelm Leibniz (1646-1716) fell this week. This is the man who gave us the calculus, as well as the binary system that made possible the computer revolution of the 20th century. This is the man who worked tirelessly to unite the Roman Catholic and Lutheran Churches, and then to unite Lutheranism, Calvinism, and Anglicanism, by seeking the common truth that underlies them all.
More notoriously, this is the man who claimed that our world is the best of all possible worlds, a doctrine aptly known as optimism. Leibniz has been derided for it ever since. But once we understand why Leibniz said that our world was the best one possible, and what he meant when he said it, we will see that the idea is not as daft as it might seem.
Leibniz believed that he could deduce from the nature of God the fact that God would create only the best possible world (with “world” here meaning “universe”). He accepted the traditional view that God’s nature is perfect, which means that he is all-powerful, all-knowing, and perfectly good.
Leibniz effectively invites us to consider God’s nature, and see what follows from it. This is his thinking: God is all-powerful, and so he can create any world he wants; God is all-knowing, and so he knows which worlds will be better than others; and God is perfectly good, and so he will want to create only the very best world.
Consequently, the only action consistent with God’s perfect nature is his creating the best possible world. If he were to create the second best world (or any other), then something would be wrong — either he would not have enough power to create the best world, or enough knowledge to know which world is best, or he would not have enough goodness to want to create it. But all of these suggestions are ridiculous, because God’s nature is perfect. As such, he will create the best possible world.
Leibniz’s conclusion has struck many as difficult to square with the evidence. Our world, with all of its wars, diseases, and natural disasters, hardly seems like the best one possible. It is easy to list all the things that we think would make the world better: less cholera, fewer earthquakes, fewer belligerent people, and so on.
This list, however, assumes that the best possible world would be the one with the least amount of bad or evil things. This is not a view that Leibniz shared. Instead, he thought that the best possible world would be the one that contains the greatest variety of things produced by the simplest ways, and that contains as much happiness as is possible.
If you are not convinced that variety is the sort of thing that adds to the world’s goodness, here is a challenge: suppose you had to make the best possible library. Would you just find the best book ever written, and purchase as many copies as your budget allowed, filling the library with only that one book? Probably not.
Would you restrict yourself to 100 choice titles, and buy as many copies of each as you could? Again, probably not. Instead, you would opt for variety: different books, by different authors, on different subjects, of varying quality. Generally, the more variety in the stock, the better the library would be.
And so it is with the universe, Leibniz argues. This is because every created thing contains some of God’s essence; so the greater the variety, the more God’s essence is multiplied.
Leibniz believed that God would produce this great variety using the simplest means possible, deducing this from God’s great wisdom. As we know from our experience, the wise always prefer simple ways of doing things over complex ones.
We would not think it wise for a builder to use complex and inefficient means of building a house when simpler ones were available, or for a computer programmer to use more complicated code than was needed to write a piece of software.
The same principle applies with God. As a master craftsman, he would use the simplest means available to him when creating the world and the things in it. Leibniz thought that this meant that God would establish a few, simple laws of nature that could themselves generate the greatest variety of things.
A consequence of God’s use of simple laws of nature is that the best possible world would be thoroughly rational, because it would be lawful, orderly, and intelligible. God’s use of simple laws of nature makes it possible for human beings to understand his creation.
Lastly, Leibniz believed that the best world would contain the greatest possible happiness, and he deduced this from God’s perfect goodness. After all, a perfectly good God would surely want to maximise happiness.
To those who think it unlikely that our world contains the greatest possible amount of happiness, Leibniz responds “Wait until all the facts are in.” The world includes not only all the events that have happened and are happening now, but those that are yet to happen, including those in the afterlife. This means, of course, that we cannot prove that our world has the greatest amount of happiness, but also that we cannot prove that it does not.
While we cannot say whether Leibniz is right about happiness, there are indications that our world may well possess the other features that Leibniz thought the best possible world would have.
In the 1950s, Einstein praised the simplicity of our laws of nature. In 1994, the Nobel Prize-winning physicist Murray Gell-Mann marvelled at how our very simple laws of nature gave rise to a wide variety of complex structures.
Even more recently, the distinguished physicist Paul Davies has claimed that our universe possesses “very special laws that guarantee a trend toward greater richness, diversity, and complexity through spontaneous self-organisation”.
On the basis of the rich creativity of our laws of nature, Professor Davies suggests: “In a certain scientific sense, we may well live in the best of all possible worlds.” So perhaps there is reason to share Leibniz’s optimism after all.
Dr Lloyd Strickland is Reader in Philosophy at Manchester Metropolitan University.