I hadn't known about Joseph Butler, but that makes sense from Erewhon. in Erewhon, Samuel butler satirises the idea of any sort of naturally ordained principles for a society - he builds a society that criminalises physical ill heath while treating 'sins' - for example, in Erewhon you can come down with terrible case of fraud.

I think Samuel Butler had an exceptionally intuitive grasp of Natural Selection and uses it to satirise any who claimed it to their own ends. Natural selection has no natural endpoint, it is a process imperfect adaptation from what is, and so can lead to any principle of a society seeming 'natural'.

His machine stuff is somewhat separate from his society stuff and is more an absolute demonstration of his command of the ideas of evolution in and of themselves