This universal Benevolence toward all Men, we may compare to that Principle of Gravitation, which perhaps extends to all Bodys in the Universe; but like the Love of Benevolence, increases as the Distance is diminish’d, and is strongest when Bodys come to touch each other. Now this increase of Attraction upon nearer Approach, is as necessary to the Frame of the Universe, as that there should be any Attraction at all. For a general Attraction, equal in all Distances, would by the Contrariety of such multitudes of equal Forces, put an end to all Regularity of Motion, and perhaps stop it altogether.--Frances Hutcheson (1726) An Inquiry into the Original of Our Ideas of Beauty and Virtue.
In a lovely paper that he delivered in Ghent on Wednesday, Tamas Demeter made good use of the eminently quotable paragraph, with its seductive comparison between benevolence and Newtonian gravity, quoted above. Ignoring Newton's strictures, Hutcheson implies that attraction is governed by sympathy (see here). The image has a non-trivial after-life in Hutheson's student and astute critic, Adam Smith ("All the different members of it are bound together by the agreeable bands of love and affection, and are, as it were, drawn to one common centre of mutual good offices," [HT Ryan Hanley]) as well as in Smith's careful reader, Wollstonecraft ("private virtue becoming the cement of public happiness, an orderly whole is consolidated by the tendency of all the parts towards a common centre,") [recall this post].
But my eye rested on the final sentence of Hutcheson's paragraph which expresses a counterfactual about the impossibility of an alternative force-law. (Not all possible alternatives, of course.) When you start thinking about it, he seems he has packed quite a bit into the claim. Hutcheson really makes two counterfactual predictions about what would happen if there was uniform gravity (so not based on distance [presumably just based on masses]) in the universe: (a) motion would stop being regular or (b) motion would stop altogether. I focus on (b) first; this is really a kind of anti-cosmogeny. It claims that the world could not have evolved with such a force law.
In fact, Hutcheson's second (b) point ("a general Attraction, equal in all Distances, would by the Contrariety of such multitudes of equal Forces...stop [motion] altogether") sounds (recall this post) akin to a claim that Clarke makes against Spinoza: “because the determination of this self-existent motion must be every way at once, the effect of it could be nothing else but a perpetual rest; it's a an argument that I have long struggled with (see this paper). For the aficionados: I am pretty sure that the then also famous Bentley-Newton correspondence got started by a (now lost) question from Bentley to Newton to rule the possibility of the solar system evolving out of a homogeneous plenum (which the English think Spinoza ought to embrace) with Newtonian force laws. Hutcheson's (b) seems 'intuitive' because one can understand the idea that all forces can cancel each other out so that there is no motion.
But one thing Hutcheson's counterfactual thought experiment, (b), requires is that matter needs to be uniformly or symmetrically distributed (through the infinite universe). Otherwise there is no reason to think that all the possible forces would simply cancel each other out from the start, forever. (We leave aside Norton dome style thought experiments--from my Marij Van Strien's work we know these were familiar in the 19th century, but there is no evidence they were really understood at the start of the 18th century [NB the wikipedia page is weak on the history].) So, contrary to the argument of the General Scholium, Hutcheson is tacitly assuming something like a plenum here (at least as the starting point of cosmogeny). Why he would do so is odd, unless the paragraph originates in an earlier polemic against Spinozism (or the impious development of Cartesianism)? This is a plausible inference, given that Hutecheson is familiar with the polemics surrounding Spinoza and Toland (see here and here), and Hutcheson is often at pains at showing and/or assuming the existence of final causes.
I have to admit I am a bit stumped by Hutcheson's first claim that motion would stop being regular with a uniform universal attraction. I don't recall Newton modeling that force law. (Newton does model alternatives to the inverse square law.) So, I'll have to check the Principia. I would guess that (regardless of initial conditions), such a force law would result in a gigantic clump of matter in the middle of the universe. But I'll chew on this.*
*I thank Tamas Demeter, Maarten Van Dyck, and Daniel Schneider for discussion. I should be blamed for any blunders in this argument.