In this paper I explore the meaning and significance of a sentence in the general scholium added to the Third edition of Newton’s Principia: No variation of things arises from blind metaphysical necessity, which must be the same always and everywhere.
In the first part of my paper I reconstruct the argument contained in it. I will argue that the argument is directed against Spinoza. I will show that that there is good evidence that this was so understood by informed contemporaries and that there is evidence that even Newton (who never mentions Spinoza) understood it thus. However, in reflecting on the details of Spinoza’s position, it is not obvious why Spinoza would be too peturbed by the argument.
In the second part of the paper I will use Clarke’s Demonstration and his correspondence with Butler to bring out the key modal features of the argument. Surprisingly enough, we’ll see that Clarke (but not Newton) shares some important commitments with Spinoza (over necessity and the PSR), and that he (Clarke) directs the argument against Toland.
In the third section of the paper, I show how indeed Toland is a legitimate target of the argument. I will also explain why Clarke and even Newton would have been threatened by Toland’s interpretation of the first edition of the Principia.
I conclude with some diagnosis of the state of play between advocates of Newton and Spinoza at the death of Newton (with a gentle nod forward toward Hume and Kant).