Note: My question assumes a conceptual distinction between minds and the external world, regardless of whether they're actually two different kinds of substances.

There seems to be widespread agreement that the universe we currently inhabit is considered physical, but what about hypothetical worlds that behave completely differently? To illustrate my point, imagine that there are several other inhabited worlds, each in their own isolated space:

  • World A is completely different from ours, but it still follows the same set of laws that we call physics. By sheer coincidence, there's an Earth-like planet in which a tomato-like species has evolved.
  • World B follows a completely different set of laws. For some reason, it still has something that resembles tomatoes.
  • World C is collectively formed and manipulated by the minds of its inhabitants, and it follows no other laws. Tomatoes can be found here too, because people like tomatoes.

All three worlds are conceptually distinct from minds (and mental properties) in exactly the same way, so they deserve a common adjective. Obviously, World A is physical, but I'm not sure whether the other two qualify. Does the adjective physical apply only to worlds that obey the laws of physics?

  • If the answer is yes, then what would be the proper adjective to describe all three worlds? Terms like objective or non-mental seem too broad, because they could also encompass certain abstract concepts (e.g. numbers).
  • If the answer is no, then what would be the proper adjective to describe only World A, or at least only World A and World B?
  • Short answer, no. At least, not if "physical laws" refers to the ones we are familiar with. The word "physical" has a complicated history with a medley of meanings from not mental-like, to tangible/corporeal, to obeying causal laws, possibly very different from ours. Your C is probably non-"physical", and there is not enough information about B, but the term is too vague for definitive answers in many hypothetical cases.
    – Conifold
    Commented Mar 1, 2019 at 8:57
  • I think physical.denotes things which can't be in the same place at the same time.. which is just one of the rules our universe seems to follow. Could.there be.a magical world, in which there are stil physical things? Yeah i don't see why not.
    – Richard
    Commented Mar 1, 2019 at 18:22
  • @Conifold The other question is broad enough to encompass mine, but it's mostly concerned with what makes this world physical, so it doesn't specifically address hypothetical "bizarre" worlds. Honestly, I can't swear that my question isn't a duplicate. It's just focused on a more specific issue, which is either a virtue or a fault.
    – Steohawk
    Commented Mar 2, 2019 at 17:08

1 Answer 1


"physical" applies to phenomena that are observable by reproducible experimental procedures. Note that the outcomes of those observations needn't be reproducible, just the procedures themselves. Laws are entirely irrelevant to whether or not the phenomena are physical. And it's indeed somewhat of a mystery (arguably related to the anthropic principle) that observable phenomena seem to be correlated by mathematical-like laws. So I don't know the answers to your A,B,C questions. But the entire "laws" premise of those questions is an overreach in the first place.

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