Review of Substance and the Fundamentality of the Familiar: A New-Aristotelian Mereology by Ross D. Inman

December 19, 2019

Inman, Ross D. Substance and the Fundamentality of the Familiar: A Neo-Aristotelian Mereology. New York, NY: Routledge, 2018, 304, $145.00, hardcover.


Ross Inman is Associate Professor of Philosophy at Southwestern Baptist Theological Seminary in Fort Worth Texas and also serves as the senior editor for the journal Philosophia Christi. He holds an M.A. in Philosophy from Talbot School of Theology and a Ph.D. in Philosophy from Trinity College, Dublin. He also completed research fellowships at the University of Notre Dame and Saint Louis University. Based upon this Inman has the necessary credentials and training to wade into the difficult waters of mereology in his book on the fundamental nature of substance.

Mereology is about wholes and their parts, determining which is most fundamental to identity and existence. The typical views in mereology affirm either the whole as prior to its parts or the parts as prior to the whole. Inman, on the other hand, defends a via media thesis that at least some intermediate composite objects like people, trees, and tigers are the most fundamental objects, being substances in their own right. Rather than following Monism or Pluralism about fundamentality in whole, where either the bottom or the top of the material chain is most fundamental, on his view, objects such as humans can be understood as fundamental (p. 4). Hence his title about the fundamentality of the familiar. Common sense dictates that objects such as tigers are “fundamental” in some sense. The smallest physical objects or the largest physical object are not exhaustive options in mereology. There is a place for intermediate substances that are not the largest object and are composed of several parts. The need for his book arises from not only a gap in mereology (most contemporary expositions of mereology find the smallest microphysical parts of the universe to be fundamental) but from a gap from within his own metaphysical camp—that of contemporary Neo-Aristotelian analytic metaphysics. It fills the void by defending an intermediate view of substances (p. 3).

Inman begins by defending what he calls “serious essentialism.” This is not a novel defense to Inman but one found in many metaphysicians fond of medieval scholasticism or Thomism. Serious essentialism claims that the world and its objective de re modal structure is carved out by the natures of things. Alternative attempts like modal essentialism are insufficient for discovering the carvings of these joints (p. 11). To know the fundamental natures of things and the grounds of metaphysical necessity and possibility requires something far more serious and fine-grained than what is often provided within the modal gloss alone. Not all metaphysical necessities are on par with one another because some are structured or ordered in ways that give definitive identity to an object (p. 24). Inman provides several examples to explain why this is so—mostly borrowing from and following Kit Fine’s influential article “Essence and Modality” from 1994.

Next, Inman explicates the nature of grounding and essence. By ‘grounding’ Inman means a “non-causal, metaphysical priority relation that obtains between composite objects and their proper parts” (p. 54). He provides several potential options for what constitutes grounding before settling on what he calls “essential grounding” which is inspired by John Duns Scotus. Essential grounding requires it to be part of the essence of an object that it exists only if its parts exist (p. 68).

Chapter 3 is dedicated to defending the priority of substance. He endeavors to promote the thesis that no fundamental entity has another fundamental entity as a proper part. Given this, there can be no more than one fundamental entity on the hierarchy of composition. Inman admits this “plays an absolutely central role in my overall neo-Aristotelian metaphysic of material objects” (p. 85). So, in contrast to the commonly held belief that all chains of metaphysical dependence run through intermediate composite objects, Inman believes some terminate in them (p. 90). For Inman, a mixed view is possible. Substances are metaphysically fundamental and are either simple or prior to their parts while aggregates are posterior to their parts or to the substance of which they are parts (p. 94). From this he provides his definition of substance which is something that is ungrounded and a unity (p. 98).

Inman then turns to critique, focusing primarily on the popular thesis of Part-Priority which thinks the smallest parts of the world are fundamental and prior to their wholes (p. 115). He explains how such a thesis cannot account for either chemical structure or biological structure. This is so because it is scientifically proven that some properties transcend their physical parts. There are facts involving natural properties instantiated by composite objects that are irreducible to facts about their natural properties alone—they cannot exist apart from the composite (p. 143).

Once he has sufficiently cast doubt on Part-Priority he shows the utility of his thesis for several metaphysical puzzles. Next he shows how substantial priority makes sense of when composition occurs. Here he argues against metaphysical vagueness on composition, claiming that there is a rigid cutoff for composition which he takes to be the instantiation of non-redundant causal powers (p. 186). In chapter 7, Inman shows further benefits of Substantial Priority. He defends the terminus argument and the tracking argument. The terminus argument claims that “only a fundamental mereology equipped with at least one fundamental intermediate can allow for a terminus of grounding chains in possible worlds with no bottom or top mereological levels” (p. 203). The tracking argument accepts the common claim that it is necessary for the fundamental causal properties of entities to track the fundamental bearers of properties. From this it claims that at least some intermediate composites are bearers of properties. Therefore, at least some intermediate composites can act as fundamental bearers of properties (p. 207). He also thinks if one rejects Substantial Priority common beliefs in free will and the existence of non-redundant phenomenal mental properties are undermined (p. 214). Finally in Chapters 8 and 9 he examines the least and most worrisome objections to Substantial Priority and provides several ways to rebut them.

Having summarized Inman’s book, it is important to note both the positive contributions it makes but also the negative aspects to offer the most helpful review. Beginning with the negatives, there are numerous abbreviations throughout the book, particularly in the opening chapters. While it is common to analytic philosophy to utilize abbreviations, when they are excessively used they sacrifice clarity. Maybe an appendix or glossary of abbreviations would help mitigate this problem. Even so, the book would have been far better served if they were removed.

Second, his introduction to serious essentialism departs from all prominent serious essentialists with an original contribution that appears suspect (p. 17). He eliminates modal essentialism in its entirety. This move is not only highly controversial but also unnecessary. There is no reason to depart from modal essentialism in its entirety in order to advance his thesis. It would be better to leave it intact as a useful tool that is simply insufficient. The purpose of modal essentialism is not to carve nature at its joints, as Inman desires, but to place minimal constraints on the data that any metaphysical explanation needs to account for. Its goal is to perspicuously describe rather than discover essential and non-essential properties. The fact that modal logic remains neutral on which metaphysical explanation is used for the truths it states, neither assuming nor requiring any particular theory (whether essentialist or non-essentialist, etc.), means that it serves metaphysics (including Inman’s serious essentialism) by leaving it plenty of work to do without eliminating potential solutions. Since this is its purpose, it is not necessary to dispense with it completely as Inman argues. While it may be insufficient it can remain as a useful supplement.

Third, the price of Inman’s work is out of the range of the ordinary reader. While it is likely priced so high to market specifically to libraries, this is a negative if others without access hope to study the work at length. While the Routledge Studies in Metaphysics is an excellent series, Inman’s work would be far more visible and accessible had it been published at a lower cost.

Having discussed several negatives, what does Inman’s book do positively? Most importantly, he charitably and honestly engages objections and counter proposals to his own thesis. Throughout the book he is even-handed and fair to all sides, bringing forth their best arguments and stating their claims clearly. At no point does he attempt to hide the faults of his own thesis, either. Neither does his writing dip into emotional pleas or silence on the best objections to his own view. It is clear at all points. Even with such a dense subject matter he manages to write in a way that is readable and enjoyable. He never writes for the sake of writing. Every sentence has purpose. Every paragraph is put to work. Nothing is wasted. Such clear and fair writing is rare in contemporary literature. Therefore, Inman provides an excellent model for all aspiring philosophers, theologians, and seasoned academics alike.

Second, his arguments against Part-Priority are excellent. For example, the structure of Hydrogen Chloride together as a composite substance obtains its acidic behavior and distinctive boiling point only in virtue of its substantial nature. The composite chemical as a whole is necessary to possess its distinctive causal powers and capacities. The elements apart from the whole lack the causal powers that are present with the whole (p. 144). If molecules such as these are to be reducible to their parts as Part-Priority maintains, they should evidence no new causal powers beyond what exists as parts. But this is not the case (p. 145). Therefore, Part-Priority cannot be correct as a complete thesis since novel properties are scientifically proven to emerge from composite substances.

Third, Inman fills a vacuum with his book. As he noted, there has been no contemporary defense of the fundamentality of substance for medium-sized composite objects. His thesis about Substantial Priority fills this void and does so admirably. So, not only is his book a superb work in metaphysics and mereology, it also packs an argumentative punch. It is crisp, clear, and useful. Anyone interested in the study of mereology will be required to reference, read, and engage the arguments Inman puts forth. It is not a bystander in its niche realm. It is a metaphysical heavy-weight that cannot be ignored. His thesis is more than just an alternative possible option but one of legitimate strength that deserves a place alongside the premier options in mereology.

In assessing this books overall contribution to theological studies, its audience must be kept in mind. This is not a beginner’s textbook, nor is it designed for undergraduates. It is designed as a novel and technical contribution to the field of mereology. Therefore, anyone attempting to glean from it should be aware that prior knowledge of metaphysics is required. For anyone lacking the requisite training and knowledge it is recommended to study several beginning textbooks on metaphysics to have a basic grasp of the overall context of the discussion. However, Inman writes in such a way that those with a beginner’s grasp of metaphysical issues will be rewarded for their hard work and diligence. It may require a second reading for such students, but it will be well worth their time.

So, how should the biblical-theological student interact with this book? First, they should recognize its audience as noted above. It is not for the faint of heart. Though it is clear in its presentation, the concepts are dense. Second, biblical-theological students should interact with the book. Just because it is more difficult does not mean it is unnecessary or unimportant. Often times the greatest theological payoffs can come from the most difficult subject matters. Inman’s tour of mereology is no different. It provides a major contribution to the field of mereology by providing a middle way for material objects. For example, the current landscape is dominated by Part-Priority views that significantly limit positions in the Philosophy of Mind which is an every growing field for those interested in theology. If one is to be competent in this area, they must know the alternative positions that allow for them to hold their preferred anthropological position. Further, as Inman suggests, if one is interested in defending either free will or non-redundant mental properties, a proper mereology must undergird it (p. 214). Both of these topics are central to many theological areas. Therefore, while mereology may be unfamiliar territory for many biblical and theological students, it is necessary for the serious student. And Inman’s work is an excellent standard by which to test and advance ones knowledge.


Jordan L. Steffaniak

Southeastern Baptist Theological Seminary

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