Only five months after the publication of Belinfante's proof of the Spin-Statistics Theorem based upon his Ph.D. dissertation Pauli wrote a critique of it. Ian Duck and E.C.G. Sudarshan in their Pauli and the Spin-Statistics Theorem say that the criticisms where not justified. Pauli brought Belinfante in as a co-author of the critique article. Duck and Sudarshan suggest that Belinfante was a less-than-eager participant to that critique of his own work. Pauli, at that time, was perhaps past his prime as a theorist.

The critique was stated in terms of the undor concept introduced by Belinfante. Pauli seems intrigued by the assumption that the systems are invariant to charge conjugation, the reassignment of charge to the particles of an assembleage. Pauli wanted to combine invariance with charge conjugation with the positive definiteness of energy.

Duck and Sudarshan say

What then about the validity of the criticisms of Belifante's proof? The conclusion is that Belifante's proof is not correct, but not for the reasons put forth by Pauli. Pauli's objections appear to us today to be contrived and artificial.

(To be continued,)

Ian Duck and E.C.G. Sudarshan, Pauli and the Spin-Statistics Theorem,, World Scientific, Singapore, 1997.