Error in civil law

Legal transactions base on intent and declaration of intent. It should be answered by doctrine, what is the effect of a mistake at the formation of the intent and declaration of it. Trust principle, which dominates private law, bases on the point of the receiver of the declaration. On the other hand, other dominating principle of the private law, which is called freedom of will dictate that someone can only be part of transactions, which are compatible with his / her intents. Regulations about the error draw the line between these two opposite principles and thus trust and freedom of will principles become suitable with each other. Within the scope of our thesis we focus firstly on the definition and types of error, afterwards analyze the effects of error on legal transactions in different branches of the civil law.