请将以下句子翻译成英文：亚当·斯密在《国富论》中提出理论和方法都是经济史学赖以建立的基础。今天的经济史学界虽然新观点、新方法、新材料、新问题不断涌现但最基本的理论基础和话语体系仍然是亚当·斯密创立的。

Adam Smith's theory and methodology, as presented in "The Wealth of Nations," laid the foundation for the establishment of economic history. In today's field of economic history, although new perspectives, methods, materials, and problems constantly emerge, the fundamental theoretical basis and discourse system are still established by Adam Smith.