Living tree doctrine is a legal concept that can be used to help courts find meaning in old laws. It says that laws should be seen as living things that evolve over time, allowing us to use our modern understanding to explain them. This means that when interpreting a law, the court looks at the meanings of words and how they were used in the time the law was written to figure out what the law was intended to do. This means that when old laws are applied to new situations, we can make sure the law still has the same effect that it originally intended to have.