General Relativity resembles a very elegant crystal glass: If we touch its principles, that is, its Lagrangian, there is a risk of breaking everything. Or, if we will, it is like a short blanket: Curing some problems creates new problems. This paper is devoted to bring to light the reasons why we pursue the possibility of a non-Lagrangian theory of gravity under the hypothesis of an extension of the original general relativity with an ansatz inspired in the fundamental principles of classical and quantum physics.

中文翻译：

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非拉格朗日引力理论的可能性

广义相对论就像一个非常优雅的水晶玻璃：如果我们触及它的原理，也就是它的拉格朗日函数，就有破坏一切的危险。或者，如果我们愿意，它就像一条毯子：解决一些问题会产生新的问题。本文致力于揭示为什么我们在原始广义相对论的扩展假设下追求非拉格朗日引力理论的可能性，并在经典和量子物理学的基本原理中受到启发。