Theory of effect of constitution rights in contract law and the position of this theory in Iranian legal system

Today in legal system of some countries including Germany, constitutional rights (fundamental rights) affect contract law greatly. So content of contracts and rules of contract law should not contradict with constitutional rights. Right to life, freedom of speech, equality and freedom of labour are examples of the most important constitutional rights.
In legal system of these countries, effect of constitutional rights in contract law accomplishes through various methods. In accordance with direct horizontal effect method a claim or defense rises directly on the base of constitutional rights against the other party. In indirect horizontal effect although a claim or defense is on the base of rules of contract law but these rules interpret in light of constitutional rights. This manner divides to strong indirect horizontal effect and weak indirect horizontal effect. Apart from direct and indirect horizontal effect, according to a different method, constitutional rights address state, and state obliged to protect constitutional rights. This method called State duties to protect constitutional rights.
Also in Iranian legal system, constitutional rights affect contract law. So persons can not devest their constitutional rights by contracts.
In a summary of what has been proposed in this paper it can be said in Iranian contract law system, manner of effect of constitutional rights is strong indirect horizontal effect.