In this category are words that people tend to use interchangeably although they have different meanings. You can affect decision-making with your vote. But if you distinguish between the words, you may effect a change in usage that will affect your writing. These words receive heavy use in the legal profession. Be sure to distinguish between them.
Principles are basic truths, rules or assumptions.
Your legal arguments will often be based upon legal rules, also called doctrines or principles . The words principal can be either a noun or an adjective. As a noun it refers to the individual or party who is first in importance, rank, or degree. Schools employ principals and vice-principals. The principal is one who has the prime obligation in a contract, or one who, in criminal law, commits a crime.