The present work has been a result of a wide investigation about the
good faith and its importance in the precontractual business's stage.
This article demonstrate the intrinsic relationship between the good
faith, morality and the good customs, making clear the role of the good
faith as a limit to the people's subjective rights. Likewise, the abuse of
law is very important for the concept of good faith, because both of them
give rise to the collateral duties and the importance of the fault for the
precontractual liability. In conclusion, the good faith represents the value
of word for the contracting parties and this concept helps the judge to
make decisions with fairness and equity.