Com a entrada em vigor do novo Código Civil, Lei n. 10.406, de 10 de janeiro de 2002, as cláusulas gerais passaram a ocupar papel de destaque no ordenamento jurídico brasileiro, em especial no direito privado. Observamos, todavia, que pouca relação tiveram as referidas cláusulas com o direito tributário, restando imperiosa uma análise dogmática objetivando esclarecer os limites dos operadores do direito no manuseio de instrumentos que arejam o sistema jurídico. Dispositivos legais como os da função social dos contratos, do abuso do direito e da fraude à lei foram consagrados fazendo necessário um exame dos métodos mais adequados para a interpretação dessa espécie normativa e principais efeitos tributários. Tenta-se ainda demonstrar que o exame da causa no negócio jurídico é tema central para a interpretação dos negócios jurídicos de direito privado que exercem influência sobre o tema da tributação.

The following work has the prime aim to investigate and to formulate conclusions on the relation between the Brazilian tax system and the Brazilian Civil Code. For about a century, starting perhaps around 1870, changes in political thought, in social and economic conditions, and in the law, began to take place at an ever-increasing pace. After the age o freedom of contract (perhaps best placed in the century between 1770 and 1870) it is not hard to identify a period of gradual decline in belief of freedom of contract. These developments during this period represented to some degree a reversion to older traditions which pre-dated the age of individualism and freedom of contract, but has equally influenced the elaboration of the Brazilian Civil Code, which came into force on 2002. There we can clearly see the freedom of the contract limited by the principal of the social destination of contract, and other general clauses such as the abuse of rights and the civil fraud. The following work intends to investigate how these specific articles of the Brazilian Civil Code influences the legal obligation to pay taxes and the freedom to make tax planning's.