“I will not reinvent the wheel.” Say it a few times. Memorize it. Make it your legal research mantra. There’s simply no need to do work that’s already been done. You already have enough to do. In most cases, what you’ll be asked to research isn’t totally new. Someone has researched it before (and someone will research it again). The trick is finding the research that’s been done and making it work for you.
That’s where legal treatises come in. Think of them as prepackaged legal research. Open them up and you’ll find a summary of the law with citations to relevant primary authority waiting for you. The work’s been done. Why do it again?
Unfortunately, most students don’t become very familiar with legal treatises in law school. Sure, they may have heard of them. Some of the names, like Williston on Contracts or Wigmore on Evidence, may even sound familiar. But, it’s rare to find a law student with a vision of how important a treatise can be.