The legal doctrine by which a person is prevented from asserting rights or facts that are inconsistent with a previous position or representation made by act, conduct or silence is known as

Estoppel

Explanation:

Estoppel is a principle in law that prevents an individual from asserting or making an argument that contradicts an initial argument or action or agreement by this person. It protects individuals from inconsistent actions or statements of others such as saying one thing and denying and saying something else that contradicts it. There are different types of estoppel such as : promissory estoppel, collateral estoppel, estoppel by deed. Promissory estoppel is a popular estoppel that protects individuals or entities against individuals or entities that do not meet their agreement or promise in contract and therefore allows the affected party act based on their promise without the other party fulfilling their part causing economic loss

true because they can bargain