Vitalik just replied to this a few days ago https://twitter.com/VitalikButerin/status/156607316409372672...

> Because it's not a circular argument, it's a spiral argument. People with coins at time T secure the transactions at time T+1.

> Spiral arguments and circular arguments sometimes look similar to untrained observers, but they are fundamentally different.

This is obviously worse because future transactions depend on people with coins in the past

Modern society is built upon shared beliefs. Dollar has value because people believe it to be so. People go to work because they believe dollar will have value in part because other people believe the same things. Comparison to circular logic is quite apt, but it applies to most of the modern wold.

bitcoin doesnt suffer this because proof of work provides an independent method for verification. the energy utilization argument that comes up should be evaluated in the context of the comparison of this independent humanless verification vs proof-of-stake or other shared or trusted mechanisms

Proof of stake still follows longest chain rules.