Philosophical Studies

, Volume 163, Issue 1, pp 133-149

First online:

How many thoughts are there? Or why we likely have no Tegmark duplicates \( 10^{{10^{115} }} \) m away

  • Douglas V. PorporaAffiliated withDepartment of Culture and Communication, Drexel University Email author 

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Physicist Max Tegmark argues that if there are infinite universes or sub-universes, we will encounter our exact duplicates infinite times, the nearest within \( 10^{{10^{115} }} \) m. Tegmark assumes Humean supervenience and a finite number of possible combinations of elementary quantum states. This paper argues on the contrary that Tegmark’s argument fails to hold if possible thoughts, persons, and life histories are all infinite in number. Are there infinite thoughts we could possibly think? This paper will show that there are. If so, then it is not only Tegmark’s specific claim about our duplication that is called into question. We additionally acquire another strong argument against Humean supervenience.


Supervenience Multiverse Personal identity Mind–body Number of mental states