In Plato's Republic, Socrates sets forth the following idea, which he later refutes:
τὸ τὰ αὑτοῦ πράττειν καὶ μὴ πολυπραγμονεῖν δικαιοσύνη ἐστί,
justice is to do one's own business and not to do too much,
What's odd, grammatically speaking, is that the compound verb πολυπραγμονεῖν ("to do a lot") doesn't use the verb stem πράττειν, which appears earlier in the clause.
Why does the compound verb πολυπραγμονεῖν use the noun stem instead of the verb stem? Is this common? I would expect to see πολυπράττειν instead.