From: Brian Holtz [brian@holtz.org] Sent: Friday, April 26, 2002 8:51 AM To: alt.atheism.moderated Subject: Re: Science & atheism are cultures. "Paul Holbach" wrote: > Sheer possible worlds (as opposed to the actual ones) are unreal, ie > they are existent only inasmuch as we imagine them as existent. How do you distinguish between possible worlds and "the actual ones" that are not this one? > Possible worlds are mental contents of imagination and nothing more. The same could be said of "actual" worlds that are not this world. > you as a modal realist are not going to agree with me on > that, but you know that Iīm very doubtful about modal realismīs > special use of "existence" and "actuality". My commitment to modal realism rests only on the absence of the distinction I asked about above. I don't know that no such distinction is possible. > itīs nonsense to claim that sheer possible worlds are just as > real as actual ones, ie they exist in the same sense as > actual worlds do. What's precisely "nonsense" is to claim that there is a difference between other possible worlds and other actual worlds without being able to say what that difference is. > if there were a state of absolute > impossibility, then there would be no actual world I agree that the actual world is evidence that absolute possibility does not obtain. I'm not sure I agree that the actual world is evidence that absolute possibility could not possibly obtain. > > I don't see how it would be self-contradictory for > > nothing to exist. > > Please take a look at my explicit argument against Buridan. I might, but I want to avoid getting involved in any more threads. > there may certainly be many other actual universes we > donīt know (yet). (How could we ever come to know that another universe is actual?) > A purely possible other world is a mind-dependent object of > imagination, whereas an actual other world is a mind-independent > entity. Whether a world is possible does not depend on any minds. What you probably mean is "a merely possible world does not have any existence independent of its possibility". But again: what precisely does 'existence' (or 'actuality') mean when applied to worlds, and how is it different from possibility? > You seem to have mixed up an epistemological issue and an > ontological one. No, I'm just noticing that 1) the ontological term 'exist', when precisely defined, only applies within worlds and not to worlds themselves; and 2) the ontological phrase 'the actual world' just means "this world". > the actuality of something is independent of its being known > as actual. I agree that our physical experience is that the existence of something is generally independent of knowledge or observations of its existence. However, quantum theory provides some exceptions to this general rule. More importantly, ontology should not just assume this rule to be true. Indeed, if something's existence is in principle absolutely impossible to know or observe in any way, then a proper ontology should hold that it does not exist, even if someone stipulates otherwise. (This is the precise notion of 'exist' that I mentioned earlier as being applicable only within worlds. If applied to worlds themselves, it would claim by fiat that other worlds cannot exist.) > Every actual world is possible, but not every possible world is > actual I'm still eagerly waiting to hear the difference between 'possible' and 'actual' when applied to worlds. > I discern a clear semantic difference here. There are definitely connotative differences between these words, but I argue that such differences are a consequence of their use within our familiar world and that such differences vanish in the context of worlds themselves. > Since I believe that only particular things exist in the world, you > cannot subtract all particulars and retain the world. Why not? Any possible world can be described by a model. What is contradictory about a world described by a model with an empty domain set? > a self-contradictory *state of affairs* is no state of > affairs at all and so there cannot be any > world which is both empty and real. I don't see how this follows. What I would instead conclude is that absolute impossibility is self-contradictory. > > the alleged fact of this self-contradiction has somehow been > > omitted from every philosophy reference work that I've ever read. > > Both absolute impossibility and absolute nothingness are untenable > concepts. Is this supposed to be an explanation why the impossibility of nothingness is omitted from philosophy reference works? -- brian@holtz.org http://humanknowledge.net