Lowery's power projection theory provides a solid foundation to support the arguments for what makes good money.
Generally, we have following characteristics for money:
Durability
Portability
Acceptability
Limited supply
Divisibility
Uniformity
The medium which projects the most power in these 6 categories will be the Schelling point of money. Said differently, that which can physically, in objective reality, demonstrate these characteristics better than any other thing is money.
But from a power projection perspective:
What will let the holder project the most power against a trading partner in the future is money.
What will give it's holder the most protection from exploitation and abuse in future trades is money.
So when taking these requirements int account, the 6 characteristics above are a very good answer to the problem, but may not always be the only answer.