We consider the modality “ is true in every -centered forcing extension,” denoted , and its dual “ is true in some -centered forcing extension,” denoted (where is a statement in set theory), which give rise to the notion of a principle of -centered forcing. We prove that if ZFC is consistent, then the modal logic of -centered forcing, i.e., the ZFC-provable principles of -centered forcing, is exactly . We also generalize this result to other related classes of forcing.