이성 (Reason) refers to the cognitive ability to think, understand, and form judgments logically. It allows individuals to analyze situations, draw conclusions, and make decisions based on evidence rather than emotions. This process is fundamental in various fields, including philosophy, science, and everyday life, as it helps people navigate complex problems and arrive at rational solutions. In philosophy, 이성 is often contrasted with 감정 (emotion), highlighting the importance of logical thinking in ethical decision-making and moral reasoning. Prominent philosophers like Immanuel Kant emphasized the role of 이성 in achieving autonomy and understanding moral laws. By relying on 이성, individuals can cultivate critical thinking skills and enhance their problem-solving abilities.