Or more simply, how do octopuses think? I'm designing a race of intelligent-but-primitive cephalopod aliens and while I want them to exhibit some basic human traits such as fear, self-interest, a social hierarchy, language, zealotry and religion, I'd also like to avoid the pitfall of making them too human. So to that end, I thought I'd take time to consider how their evolution and physiology might affect their psychology, and then work in history on top of that. The problem is, I don't really have any understanding of how an octopus on Earth might think compared to a human. I'm aware that this is a question without any really good answers since scientists are still struggling with this line of inquiry themselves, but a rough idea or even conjecture about how a creature that's evolved distributed intelligence might think differently than a human would help a lot.
A few cliff-notes about this species: they're blind but communicate via bioluminescence using light-sensitive proteins in their skin (to compensate for the total darkness of Europa's oceans; fully-formed eyes would be relatively wasteful), they lack both the pigmentation and chromatophores present in most Earth species, they're about as large as a pacific giant octopus, possess a large quantity of cilia lining their arms around their suckers that they use for fine manipulation and to signal complex ideas requiring elaborate color displays, and their society is highly religious, revolving around the worship of a single omnipotent sea god (I can explain this in further detail if you think it's relevant, but I'm trying to focus on the purely biological aspects right now).