The history of modern economics abounds with pleas for more pluralism as well as pleas for more unification. These seem to be contradictory goals, suggesting that pluralism and unification are mutually exclusive, or at least that they involve trade-offs with more of one necessarily being traded off against less of the other. This paper will use the example of Paul Samuelson's Foundations of Economic Analysis (1947) to argue that the relationship between pluralism and unification is often more complex than this simple dichotomy suggests. In particular, Samuelson's Foundations is invariably presented as a key text in the unification of modern economics during the middle of the twentieth century; and in many ways that is entirely correct. But Samuelson's unification was not at the theoretical (causal and explanatory) level, but rather at the purely mathematical derivational level. Although this fact is recognized in the literature on Samuelson, what seems to be less recognized is that for Samuelson, much of the motivation for this unification was pluralist in spirit: not to narrow scientific economics into one single theory, but rather to allow for more than one theory to co-exist under a single unified derivational technique. This hidden pluralism will be discussed in detail. The paper concludes with a discussion of the implications for more recent developments in economics.

现代经济学的历史充满了对更加多元化和更加统一的呼吁。这些似乎是相互矛盾的目标，表明多元主义和统一是相互排斥的，或者至少它们涉及权衡，其中更多的必然与更少的另一种进行权衡。本文将使用保罗·萨缪尔森（Paul Samuelson）的经济分析基础（1947）的例子来论证多元主义与统一之间的关系往往比这种简单的二分法所暗示的更为复杂。特别是萨缪尔森基金会总是作为二十世纪中叶现代经济学统一的关键文本提出；在许多方面这是完全正确的。但萨缪尔森的统一不是在理论（因果和解释）层面，而是在纯粹的数学推导层面。尽管这一事实在有关萨缪尔森的文献中得到了承认，但似乎不太被承认的是，对于萨缪尔森来说，这种统一的大部分动机在精神上是多元化的：不是将科学经济学缩小为一个单一的理论，而是允许更多而不是一个理论在单一统一的推导技术下共存。将详细讨论这种隐藏的多元化。本文最后讨论了对最近经济学发展的影响。