Every principle of justice should be written out plainly so we can all agree. That is the purpose of maxims, so we can agree what justice is and what it is not. Only in agreement can we maintain our form of government and pass it on to our children. Suppose you sign a contract prepared for you by a man who is selling you a house. If you sue, the court will construe the ambiguities in a light most favorable to you and against the seller who drafted his own contract.
Maxims promote fairness without which justice is impossible.
Indeed, maxims define the limits courts must put on judgments so justice is served. Courts are not free to rule any way the judge pleases. Judges must obey the law and stay within the boundaries established by maxims such as this. Lift the lamp higher. Teach the maxims of law.