You're conflating paradigms (program design philosophies) with language features (program design tools): (0) Functional programming is a paradigm that encourag

You're conflating paradigms (program design philosophies) with language features (program design tools): (0) Functional programming is a paradigm that encourages expressing computation as expression evaluation, and discourages relying on more computational effects than are necessary to obtain a desired result. (1) Object-oriented programming is a paradigm that discourages directly manipulating data structures from different parts of a program. Objects expose operations that act on a data structure hidden from the rest of the program. (2) Effect segregation is a feature of some programming languages, notably Haskell and its descendants. An effect system classifies computations according to their possible effects, just like a type system classifies computations according to their possible results. You wouldn't call static typing a paradigm, right?