Deductive logic is a method of reasoning that starts with general statements or premises and leads to a specific conclusion. It operates on the principle that if the premises are true, the conclusion must also be true. For example, if we know that all humans are mortal and that Socrates is a human, we can deduce that Socrates is mortal. This type of logic is often used in mathematics and philosophy, where clear and structured arguments are essential. Deductive reasoning helps ensure that conclusions are logically sound and based on established facts, making it a fundamental tool in critical thinking and problem-solving.