For those interested, the article is actually called &quot;What Numbers Could not Be&quot; (many references have &quot;What Numbers Cannot Be&quot; so maybe it was published under both names at some point?)<p>There is a copy at:<p><a href="http:&#x2F;&#x2F;isites.harvard.edu&#x2F;fs&#x2F;docs&#x2F;icb.topic1240846.files&#x2F;Benacerraf.pdf" rel="nofollow">http:&#x2F;&#x2F;isites.harvard.edu&#x2F;fs&#x2F;docs&#x2F;icb.topic1240846.files&#x2F;Ben...</a>