Whereas Mereological Essentialism is the thesis that the parts of an object are essential to it, Reverse Mereological Essentialism is the thesis that the whole is essential to its parts. Specifically—since RME is an Aristotelian doctrine—it is a claim not about objects in general but about substances. Here I set out and explain RME as it should be understood from the perspective of the Aristotelian-Scholastic tradition, as well as proposing a kind of master argument for believing it. A number of objections (many of which have been raised by Kathrin Koslicki or Robert Koons) are then considered, the replies to which help further to clarify and motivate RME. The final section considers some important questions concerning parts and matter in light of Ross Inman’s recent defence of RME under the guise of what he calls Substantial Priority. Considering these questions further illustrates right and wrong ways of understanding RME. Overall, the case for Reverse Mereological Essentialism is strong albeit with a number of difficulties that need to be resolved through further investigation.

分体本质论认为物体的各个部分对其至关重要，而反向分体本质论则认为整体对其部分是必不可少的。具体来说——因为 RME 是亚里士多德的学说——它不是关于一般对象而是关于实体的主张。在这里，我从亚里士多德-经院传统的角度来阐述和解释 RME，并提出一种相信它的主要论据。然后考虑了一些反对意见（其中许多是 Kathrin Koslicki 或 Robert Koons 提出的），对这些反对意见的答复有助于进一步澄清和激励 RME。最后一节根据 Ross Inman 最近打着他所谓的实质性优先权的幌子为 RME 辩护，考虑了一些关于零件和物质的重要问题。考虑这些问题进一步说明了理解 RME 的正确和错误方法。总的来说，反向分体本质论的理由很充分，尽管有许多困难需要通过进一步调查来解决。