A justification is the explanation or reasoning someone gives to show why they did something or why something is right or acceptable. When you offer a justification for missing homework, you might explain that you had a family emergency. When a scientist provides justification for a theory, she presents evidence and logic that support her conclusions.

A real justification gives solid reasons that help others understand your actions or beliefs. If you want to stay up past bedtime, saying “because I want to” isn't much of a justification, but explaining that you're finishing an important project due tomorrow provides genuine reasoning.

In writing, justification also refers to how text lines up on a page. Left-justified text has a straight left edge, while fully justified text has straight edges on both sides, like in many books and newspapers.

People sometimes hunt for justifications to defend choices they've already made, rather than making choices based on good reasons in the first place. When you justify your decisions with clear reasoning, others can understand your thinking even when they disagree with your conclusion.