(1) The research methods of philosophy are mainly speculation, while the west is speculation, China is introspection and India is meditation, but they are all the same. You can regard them as reflection. The main ways of speculation are ① induction, ② deduction and ③ epiphany; This is not detailed;

(2) The function of philosophical research method is to draw a clear line, and to what extent and breadth one thing can be achieved; There is also a systematic theory of what to do, so that what to do is rigorous and orderly;

(3)(4) No research.