Metaphysical Convergence

    Metaphysical convergence is when the same conclusion or idea occurs in different metaphysical systems but is reached by a derivation from different sets of principles.  I chose convergence because of the similarity to convergent evolution, when species evolve similar features, though they are not closely related in terms of a recent common ancestor.  

    In a post at the end of October, "Man and woman is primary - masculine and feminine are secondary abstractions" Bruce Charlton writes: 

    "the soul of a Man is either a man's or a woman's soul.  This is a fact that carries-through whatever happens in mortal life - which carries through attributes, biology, psychology and social roles."

    I commented, saying that Virgil seems to have thought something similar because in the Aeneid, Aeneas encounters the soul of Caeneus in the underworld: 

    "Caeneus, once a youth, now a woman, and again turned back by Fate into her form of old.

    Although Caeneus turned into a man physically, the soul was a woman's soul.  

    Bruce Charlton responded by saying: 

    "Well, Virgil certainly did not have the metaphysical assumptions which I do.  Presumably this is a specific coincidence of conclusions, rather than the same baseline reality."

    And this is an interesting fact if you think about it.  Here we have two fairly different metaphysical foundations giving the same conclusion.  

    One way I find this helpful to think about is by drawing connections to mathematics.  For instance, it is well-known that in addition to the familiar Euclidean geometry, there is also Non-Euclidean geometry, which was discovered when it was realized that the parallel postulate could be replaced with two different postulates, each of which gave consistent geometries.  But in addition, there is also absolute geometry, which consists of those geometric facts which do not depend on the parallel postulate for their proof and hence are true in both Euclidean and Non-Euclidean geometry.  

    The analogy is that we may have a set of metaphysical assumptions where if one or more are changed, then we can derive completely a different metaphysics from the new assumptions.  This is expected, but what is also interesting is that there may be some conclusions that hold between both sets of assumptions.  

    Another situation that might happen is when different metaphysical systems give different justifications for the same conclusions.  They both reach the same place by a different route.  

    Also interesting is, the parallel postulate article lists many statements that are mathematically equivalent to the parallel postulate.  Mathematically equivalent does not necessarily mean that they are saying exactly the same thing, but rather means that given the parallel postulate and the rest of the Euclidean axioms, one can prove the equivalent statement.  And, conversely, given the equivalent statement, and the other axioms, one can derive the parallel postulate.  Two mathematically equivalent statements stand or fall together, if one is true, then so is the other and if one is false, then the other is as well.  

    And there may be something similar in metaphysics as well, metaphysical assumptions that also stand or fall together.  

    Another possibility is metaphysical independence.  Just as the parallel postulate is independent of the other axioms of Euclidean geometry, that is, they can neither prove it nor disprove it, there may be questions that can be asked within any particular metaphysics that can neither be concluded true nor false within this metaphysics.  More assumptions are needed.  

    One could call the study of different metaphysical systems and how they relate meta-metaphysics, perhaps. 

    I do not have any particular thoughts on these matters in this post, but I believe that thinking about these kinds of things could be useful.  I am curious if any readers have any thoughts about or examples of metaphysical convergence or other matters in meta-metaphysics.  


  1. I think an example of 'metaphysical convergence' might actually serve to show that - when it is genuine - the phenomenon is not really due to convergence!

    Christianity has been explained for many hundreds of years by variations on a classical metaphysics wherein, for example, God is monotheistic (albeit a Trinity), omnipotent and omniscient - and the need for Jesus is explained in terms of original sin.

    But Mormon theology explains Christianity on the basis of an extremely different metaphysical scheme - with many Gods, and an 'evolutionary' understanding; and without original sin.

    Yet Mormon Christianity, at the end of the day, is very similar to some types of mainstream Christianity - beliefs are similar, ideal behaviour is similar etc. Someone who was not a Christian would probably see little difference (at the personal level) between an evangelical conservative protestant and a Mormon - despite their massively different metaphysical assumptions.

    Once I had understood Mormon theology, I found this remarkable - but the way I interpreted it was that there is a 'thing' which is Christianity - and different people and traditions try to explain it abstractly and simply; and the different metaphysics are the different ways they explain it.

    So Mormons, Catholics, Protestants are metaphysically-different ways of being 'a Christian' - but it is not really a matter of convergence, but divergence! Divergent ways of trying to explain the same phenomenon - each limited by the limits of human understanding, motivation etc.

    One metaphysics may be better at explaining than another (just as one scientific theory may be better than another) but none can be regarded as entirely correct because each is trying to summarize 'reality' very briefly and selectively.

    So all metaphysical formulations will fail at some points (each being partial and biased) - nonetheless some metaphysical explanations may explain some of the most important things, better than others.

  2. Good comment.

    I think you're right that divergence occurs when something is taken as given by different metaphysics and then explained by them. ​

    I suppose a pure example of convergence would be when conclusions in two different systems are derived from different principles and somehow still line up. But I cannot think of an example right now.

    Thinking more about it, I think the other kind of convergence would be a detail from two metaphysics that agrees even though it is not given equal emphasis or treated exactly the same by them both. In that case, it could be an example of independent insight into the nature of reality, but elaborated upon differently.


The real AI agenda

    On a post  by Wm Briggs, about artificial intelligence, a commenter with the monniker "ItsAllBullshit" writes:           "...