A Comparative Study of Good Faith in Countries with Written Law and Common Law

Although the concept of good faith is one of the legacies of ancient Roman law, its close relationship with ethics has caused the aspects and effects of this concept to have an important place in the legal system of most countries. The principle of good faith and fair dealing in contracts has not only had significant influence in countries with written law - countries that have been pioneers in formulating and expanding this principle - but also in the countries with the common law. The concept of good faith, its scope and consequently how it is accepted and applied in these countries is different from the view of written law countries in many ways. The development and concept of this theory, its examples, cases of application and also its effects on contracts have proponents and opponents who have each approached it with a different perspective and for their own reasons. In this article, we try to identify the place of good faith in the legal system of written law countries and customary law in international law, and by analyzing the legal system of these countries, we seek to examine the place of good faith in the legal system of written law and customary law.