Christianity
Samuel Butler had an interest in Christianity that lasted throughout his life; this interest is reflected in the book and is a prominent theme from beginning to end. For example, Ernest learns the difference between high and low Anglicanism, between Anglicanism and Roman Catholicism, and between Evangelism and Ritualism, all before he was ordained as a member of the clergy. The novel can sometimes be considered anti-Christianity, but it is in fact more anti-Church than anti-religion. It also presents Christianity as the best of all religions. He considers it a life-affirming and positive creed, grounded in a mixture of scientific thought and faith or belief. It also, in Ernest's opinion (and therefore most likely Butler's as well) encourages us to be kind and create pleasure, whilst rejecting that which is unkind, and creates unhappiness.
The Hypocrisy of Anglicanism
Butler considers Anglicanism to represent everything that is negative and hypocritical about religion and puts the blame for any "bad press" that religion has garnered firmly at Anglicanism's front door. He dislikes that is is an "all or nothing" faith (one is required to be one hundred percent pious, and effort made towards goodness is not counted, only absolute goodness matters in Anglicanism). He also finds that it attracts the most arrogant and hypocritical of worshippers who care more about being seen to be religious than actually living in a way that represents what the Word of God has actually taught them. He also detests the way in which the Anglican church eschews anything scientific even when it is logical and sensible.
Victorian Snobbery
Ernest believes that he does not conform to the Victorian ideals that are basically routed in passing judgement and in snobbery. He considers Victorian society as a whole to be entirely hypocritical, promoting the idea that as long as one is seen to do something it does not matter at all what one is doing when unseen. However, one of the book's many ironies is that Ernest also displays much of this social hypocrisy. The main example of this is when he assaults Miss Maitland, believing her to be a woman of dubious moral character, based entirely on the fact that she is rooming in a boarding house. In Victorian times, most "nice girls" did not do this and Ernest's assumption that she was "that kind of girl" based entirely on this basic judgement shows his own adherence to the snobbery that was the backbone of Victorian England.
Abusive Behavior
Theobald is an abusive parent, physically and mentally while his children are minors and powerless to stand up to him, and emotionally abusive once they are well within their rights to fight back physically. He is a brute. Once his kids are grown, he goes out of his way to irritate and upset them, and this tendency illustrates the general theme of abusive behavior and demonstrates the principle of once an abuser, always an abuser.
