This comprehensive French textbook offers a systematic introduction to moral philosophy and its connections with mathematics, designed specifically for students preparing for the competitive Grandes Écoles examinations. Over 560 pages, the author presents key ethical concepts, historical debates, and logical reasoning techniques, while integrating mathematical examples that illustrate the structure of moral arguments. The work balances theoretical exposition with practical exercises, enabling readers to develop critical thinking skills essential for both philosophical inquiry and quantitative analysis. Structured in clear sections, it serves as both a study guide and a reference source for advanced secondary‑level and early university students seeking a rigorous foundation in moral theory and its analytical applications.