The way I see it is that the FP school is about the microcosm like quantum mechanics, deciding what are the best possible building blocks of programs, the funct

The way I see it is that the FP school is about the microcosm like quantum mechanics, deciding what are the best possible building blocks of programs, the functions, which are pure and referentially transparent and immutable. OO is looking at the macro level: What are the systems how they communicate in a way that preserves the referential integrity of the system as it evolves over time. OO is like cosmology, structure of things on a large scale. FP = Quantum Mechanics OO = Relativity