1. Introduction 2. Two Competing Analyses 2.1. Conditional Perfection from the I-Principle 2.2. Conditional Perfection from the Q-Principle 2.3 Song's (2003) Analysis 3. Song's (2003) Problems and a Remedy 3.1 Song's (2003) Problems 3.2. Implicature Computation Based on the NoRedundancy Principle 3.3 A New Approach to Conditional Perfection 4. Concluding Remarks References