Leibniz advances three doctrines:
Today we are talking about the first two, theism and determinism. They raise questions about free will and what responsibility God has for evil in the world.
Leibniz maintains that God created the best of all possible worlds. To be more precise, he created the world as it is because this is the best. It is not the best because he created it.
That raises a question: does this mean that God is limited? Could he have chosen something that is not as good as the best world (Leibniz [1686] 2019, 253–54)? Leibniz maintains both that God could have chosen a different world and also that he would not do so, given his nature. This, he thinks, is good enough to show that God acted freely despite the fact that the standards for the best world are independent of his will and there is only one world that satisfies them.
But how do we determine what makes one world better than another? Leibniz appeals to a kind of efficiency: “the simplest in hypotheses and richest in phenomena” (Leibniz [1686] 2019, 255R). Similarly, he says that God chooses the simplest laws of nature that produce the maximal good effects (Leibniz [1686] 2019, 254R) and that God does nothing that is not orderly and regular (Leibniz [1686] 2019, 255).
To explain his meaning, Leibniz make analogies with human craftspeople, like architects, machinists, and authors (Leibniz [1686] 2019, 254R). I raised questions about whether those analogies are appropriate. Human beings face limits that God does not, after all. Leibniz has an answer (see Leibniz [1686] 2019, 255L).
Leibniz’s doctrine that this is the best of all possible worlds was lampooned in Voltaire’s Candide. This, in turn, was the basis for a Broadway show that features a very funny song in which a character who represents Leibniz fields a variety of skeptical questions about how this could be the best of all possible worlds.
If you will recall, we identified three uses of substance:
Distinction between what things really are and what we know about them (attributes).
Individuation: what makes one thing different from another?
Identity through change: what makes a thing stay the same when its knowable attributes change?
Leibniz is mostly interested in the second and third uses of substances: what makes one thing different from another and makes a thing remain the same despite changes.
He thinks that the world is composed of individual substances: one for every thing that exists. He also believes that each substance “contains” all of its predicates, that is, all the true things that can be said about it.
the nature of an individual substance or of a complete being is to have a notion so complete that it is sufficient to contain and to allow us to deduce from it all the predicates of the subject to which the notion is attributed. (Leibniz [1686] 2019, 256R)
Here is an example of what he means.
On the other hand, God, seeing Alexander’s individual notion of haecceity [“thisness”] sees in it at the same time the basis and reason for all the predicates which can be said truly of him, for example, that he vanquished Darius and Porus; he even knows a priori (and not by experience) whether he died a natural death or whether he was poisoned, something we can know only through history. Thus when we consider carefully the connection of things, we can say that from all time in Alexander’s soul there are vestiges of everything that has happened to him and marks of everything that will happen to him and even traces of everything that happens in the universe, even though God alone could recognize them all. (Leibniz [1686] 2019, 256R)
You will need to know why Leibniz thought that each substance had to mirror everything in the universe. Think about causal connections.
One consequence of this is a doctrine that Leibniz is famous for: the identity of indiscernables, according to which two things with exactly the same properties are the same: “it is not true that two substances can resemble each other completely and differ only in number” (Leibniz [1686] 2019, 257L).
If each of us is a substance and every truth about our past and future lives is included in that substance, then the course of our lives is determined. Leibniz accepts that. He denies that this means that everything that happens to us is necessary.
It is necessary that the sum of the interior angles of a triangle is 180 degrees. But it is not necessary that I ate lunch today. There is a possible world in which I did not do so.2 This is so even thought I was determined to eat lunch here in this world.
Judas had to betray Jesus because doing so was in his nature. Otherwise, he would not have been himself. (Leibniz [1686] 2019, 270). Given that, Leibniz does not think Judas has any grounds for complaint if he is punished.
Does this make God responsible for sin? He created Judas because doing so was in his nature. Judas is part of the best of all possible worlds and God always chooses the best.
Leibniz is asserting that this is enough to justify God’s actions: they are for the best because they are part of the best of all possible worlds. I wonder why he did not think the same thing about Judas’s actions.
Hywel David Lewis Encyclopaedia Britannica, accessed March 3, 2025.↩︎
Anjali had a great point here. Since what I am is defined by every true proposition about me, including those that will happen in the future, would it be me who did not eat lunch in the other possible world?↩︎