This Open Access Book Is A Superb Collection Of Some Fifteen Chapters Inspired By Schroeder-heister's Groundbreaking Work, Written By Leading Experts In The Field, Plus An Extensive Autobiography And Comments On The Various Contributions By Schroeder-heister Himself. For Several Decades, Peter Schroeder-heister Has Been A Central Figure In Proof-theoretic Semantics, A Field Of Study Situated At The Interface Of Logic, Theoretical Computer Science, Natural-language Semantics, And The Philosophy Of Language. The Chapters Of Which This Book Is Composed Discuss The Subject From A Rich Variety Of Angles, Including The History Of Logic, The Proper Interpretation Of Logical Validity, Natural Deduction Rules, The Notions Of Harmony And Of Synonymy, The Structure Of Proofs, The Logical Status Of Equality, Intentional Phenomena, And The Proof Theory Of Second-order Arithmetic.