I can't see how his categorisation works. Existence is generally considered to be a property of "kicking back" - of something existing independently of us, and not conforming to whatever we'd like it to be. For example. a planet is generally considered to exist - we can observer it (or land things on it) and discover unexpected results - Mars is *not* covered in H.G.Wells' Martian civilisation or Ray Bradbury's crystal cities, no matter how much we might want it to be. God (in the conventional sense of supreme being who created the universe) is sometimes considered not to exist because it's a concept that gets modified to account for new scientific discoveries - few Christians nowadays consider that God created the Earth 6000 years ago, or directly caused it to be entirely flooded, for example.
Roberto Unger and Lee Smolin are trying to claim that something can exist (kick back - or as they put it, have rigid properties) yet not have existed prior to being thought of by human minds. It seems hard to reconcile these properties. Something thought up that describes something that exists could reasonably be called an accurate scientific theory; something thought up that describes something that doesn't exist could reasonably be called fictional (or a failed scientific theory). I can see no reason why a fiction should have rigid properties. Conversely, if the subject of some theory kicks back, it's reasonable to consider it a (possibly) accurate theory describing something that should be considered (at least provisionally) real. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
