Autonomy of will (private autonomy) is the first value of private law and the principle of private autonomy is its first principle, because private law would not exist without them. Many other principles adhered to by private law (respect of good morals, honesty, neminem laedere, prohibition of abuse of rights, pacta sunt servanda, etc.), would lose its function without autonomy of will. By the way, also private law concepts can be understood and interpreted on the basis of the principle of autonomy of will. “Autonomy is the ground of the dignity of the human and of every rational nature” (Kant). Private autonomy is derived from personal freedom. The article notices that this key term disappeared from Slovak and Czech law of the socialist era, because also civil law then perceived an individual as a component of a social “machine” building up communism. Freedom and hence private autonomy are now protected by constitutional safeguards that limit the public power. The author takes note of the contradictory phenomena of modern times and the contending trends of protection of freedom of an individual to mould his or her own private affairs independently and on his or her own responsibility according to his or her own will, but also its limitation under the slogan of public interests, security and public order.