This book offers first time translations of the initial (1781-1789) critical reactions to Kant's philosophy. Also included is a selection of writings by Kant's contemporaries who took on the task of defending the critical philosophy against early attacks. This collection, which includes a glossary of key terms and biographical sketches of the critics on both sides of the debate, is a major addition to Kant scholarship and should be seen as a companion volume to the Cambridge Edition of the Works of Immanuel Kant.