It is a judicial response to concrete and pressing problems, and being a jurisprudential and doctrinal response and not a legislative one, it has developed gradually. It means that no one can change their behavior unjustifiably when they have generated in others an expectation of future behavior.
It is a jurisprudential response created on the fly, and constitutes an immediate and direct derivation of the principle of good faith. The concrete thing is that good faith does not allow the change of attitude to the detriment of third parties, when the previous behavior has generated in them expectations of future behavior.
With different formulas, in an infinite number of pronouncements, their direct and indescribable relationship or their correspondence with good faith has been recorded, specifying in some Spanish decisions that “it is a principle of the general theory of law that the contradiction is inadmissible with a Own prior conduct as a requirement of good faith “2; In addition, practically all doctrinaires see the prohibition of marching against the previous behavior as a direct derivation of good faith.
But to better understand the idea and its formulation, it is necessary to transcribe a ruling of the Supreme Court of Spain that declared:
The general rule according to which you cannot oppose your own acts, denying the legal effect of the contrary behavior, is based on good faith or, in other words, on the protection of the trust that the act or conduct objectively provokes in another.. The center of gravity of the rule does not lie in the will of its author, but in the trust generated in third parties, nor in seeing a manifestation of the value of a negotiated declaration of will manifested by facts or conclusive facts. The rule is not a derivation of the doctrine of legal business, but has its own substantivity, based on the principle of good faith.
Therefore, the direct relationship between the doctrine of the acts themselves and the general principle of good faith and consequently, the prohibition of incoherent or inconsistent behavior is not discussed and finds sufficient basis in the norm of each order that receives the principle general in good faith, such as article 1198 of the Argentine Civil Code or article 83 of the Colombian Constitution.
