BrisbaniteNine

Just to clarify, are you saying they should merely be restricted to those with training, or that they are unsuitable for your cages?

Bentham writes about this in the 18th century in 'An Introduction to the Principles of Morals and Legislation', and his answer is that it's an underpinning assumption and basically to trust him. It's self-evident, perhaps.

In responding to the notion that happiness/utility is the only inherent good, Bentham says '[h]as the rectitude of this principle been ever formally contested? It should seem that it had, by those who have not known what they have been meaning. Is it susceptible of any direct proof? it should seem not: for that which is used to prove every thing else, cannot itself be proved: a chain of proofs must have their commencement somewhere. To give such proof is as impossible as it is needless.'

E: was the 18th century.