Two striking claims are advanced on behalf of the free energy principle (FEP) in cognitive science and philosophy: (i) that it identifies a condition of the possibility of existence for self-organising systems; and (ii) that it has important implications for our understanding of how the brain works, defining a set of process theories—roughly, theories of the structure and functions of neural mechanisms—consistent with the free energy minimising imperative that it derives as a necessary feature of all self-organising systems. I argue that the conjunction of claims (i) and (ii) rests on a fallacy of equivocation. The FEP can be interpreted in two ways: as a claim about how it is possible to redescribe the existence of self-organising systems (the Descriptive FEP), and as a claim about how such systems maintain their existence (the Explanatory FEP). Although the Descriptive FEP plausibly does identify a condition of the possibility of existence for self-organising systems, it has no important implications for our understanding of how the brain works. Although the Explanatory FEP would have such implications if it were true, it does not identify a condition of the possibility of existence for self-organising systems. I consider various ways of responding to this conclusion, and I explore its implications for the role and importance of the FEP in cognitive science and philosophy.

代表认知科学和哲学中的自由能原理 (FEP) 提出了两个引人注目的主张：(i) 它确定了自组织系统存在的可能性的条件；(ii) 它对我们理解大脑如何工作具有重要意义，定义了一组过程理论——粗略地说，神经机制的结构和功能理论——与自由能最小化的必要性一致所有自组织系统的特征。我认为，主张 (i) 和 (ii) 的结合是基于模棱两可的谬误。FEP 可以用两种方式解释：作为关于如何重新描述自组织系统的存在的声明（描述性 FEP)，以及关于此类系统如何维持其存在的声明（解释性 FEP）。尽管描述性 FEP 确实确定了自组织系统存在的可能性的条件，但它对我们理解大脑如何工作没有重要意义。尽管解释性 FEP 如果为真会产生这样的影响，但它没有确定自组织系统存在的可能性的条件。我考虑了对这一结论的各种回应方式，并探讨了它对 FEP 在认知科学和哲学中的作用和重要性的影响。