Definition - What does Treatise mean?
A treatise is legal publication that discusses a particular area of law at length. Treatises provide information such as important cases, rulings and other information relating to the topic.
Lawyers use treatises to help them review the topic and gather any relevant information that they may need for a particular case.
Justipedia explains Treatise
Treatises cover different areas of law. For example, one treatise may cover criminal law, another one property law, another one tax law, etc. It is common for lawyers to work in one area of law, so a lawyer may really only need to focus on one type of treatise.
A lawyer may use a treatise to find a particular case study that is relevant to the trial that he or she is currently working on. The ruling from the case study in the treatise could be helpful for the lawyer's current case.