Why are principals liable for the torts committed by agents when they are acting within the scope of their employment?

Why are principals liable for the torts committed by agents when they are acting within the scope of their employment? Discuss with an example


This makes the principle liable in the event that they hire someone to commit a crime they know, despite that they don’t perform that themselves they are equally liable. This applies as a general common law where one is deemed to commit crime although they never do it themselves. An example is where a politician hires goons to assassinate a competing
politician. Such a politician is as equally guilty as the goon who commits murder