theme

The major theme can be debated, but I would say it's education. Not "school learning" but rather being open to learning about oneself and questioning one's identity in terms of what one learns. Where Pip learns about the world under his new wealth, he actually gets further away from who he truly is - a kind and simple boy - and only through many trials comes around to being aware of the world around him, its cruelties and unfairnesses, and accepting his identity as a bright light in all of that.

ambition and self improvement: the moral theme of great expectation is quite simple; affection,loyalty, conscience is the more important than social improvement class