Friday, May 31, 2019

Gunk, etc.

If we think parts are explanatorily prior to wholes, then gunky objects—objects which have parts but no smallest parts—involve a vicious explanatory regress. But if one takes the Aristotelian view that wholes are prior to parts, then the regress involved in gunky objects doesn’t look vicious at all: the whole is prior to some parts, these parts are prior to others, and so on ad infinitum. It’s just like a forward causal regress: today’s state causes tomorrow, tomorrow’s causes the next day’s, and so on ad infinitum.

On the other hand, on the view that parts are explanatorily prior to wholes, upward compositional regresses are unproblematic: the head is a part of the cow, the cow is a part of the earth, the earth is a part of the solar system, the solar system is a part of the Orion arm, the Orion arm is a part of the Milky Way, the Milky Way is a part of the Local Group, and this could go on forever. The Aristotelian, on the other hand, has to halt upward regresses at substances, say, cows.

This suggests that nobody should accept an ontologically serious version of the Leibniz story on which composition goes infinitely far both downward and upward, and that it is fortunate that Leibniz doesn’t accept an ontologically serious version of that story, because only the monads and their inner states are to be taken ontologically seriously. But that's not quite right. For there is a third view, namely that parthood does not involve either direction of dependence: neither do parts depend on wholes nor do wholes depend on parts. I haven't met this view in practice, though.


Ross Inman said...

Alex, good stuff here and plenty to ponder. I’ve argued in print for a view where the direction of mereological grounding tracks the kind of object in question, whether a substance or an aggregate, rather than the parthood relation. An ontology with both fundamental substances and derivative aggregates can allow for both the possibility of gunky and junky worlds, while maintaining that grounding is well-founded. See ch.3 and ch 7 of my Substance and the Fundamentality of the Familiar, if interested.

Alexander R Pruss said...


This kind of a view suggests to me that "is a part of" may actually be a disjunctive relation: the parts of an aggregate and those of an organic whole are parts at best analogically.