Section 1.1: The Factual Inaccuracies of Analytic Metaphysics

Metaphysics is expected to engage with ontological claims that are not just true, but necessarily true. This is essential because only necessarily true propositions can be established a priori, independent of empirical evidence, which is what analytic metaphysicians aim for. Yet, Humphreys points out that many metaphysical assertions are not only not necessarily true but are definitively false.

The issue, as Humphreys clarifies, does not lie in the falsity of isolated claims. After all, science has also made assertions that later proved to be incorrect. The crux of the matter is that some claims from analytic metaphysicians are (a) incompatible with well-established knowledge; (b) that such knowledge is easily accessible to specialists (e.g., physicists); and (c) that metaphysicians could grasp this knowledge with minimal effort.

Humphreys discusses a rather esoteric example: David Lewis' so-called Humean supervenience program. This physicalist claim posits that ontology is solely composed of local points in space-time and the properties that exist at those points. Everything else derives from these space-time points and their attributes.

Supervenience is a prevalent concept in metaphysics that can be illustrated through an example: the total amount of money in my pocket depends on the specific combination of bills and coins I have. To change the total, one must alter the specific composition of the currency. However, if I substitute a $10 bill for a $20 bill, the total changes to $30. Thus, Lewis suggests that all properties of objects in the world depend on the properties of local space-time points, akin to how the total amount of money depends on the specific currency composition.

The critical flaw, however, is that Humean supervenience has been shown to be factually inaccurate by contemporary physics. This incompatibility with the concept of entangled states in quantum mechanics should have been apparent to Lewis, indicating that further consideration of Humean supervenience is unwarranted.

Section 1.2: The Reliability of Intuitions

Analytic metaphysicians often lean heavily on their intuitions, using them as the foundation for their explorations and as the "data" to validate their assertions. Yet, Humphreys highlights that philosophers frequently have radically differing intuitions regarding the same issues. For instance, David Chalmers firmly believes that "philosophical zombies" are plausible—entities indistinguishable from humans but devoid of conscious experience. In contrast, I contend that the concept of p-zombies is nonsensical. Who holds the correct viewpoint? On what basis?

Moreover, psychological research suggests that no individual can be deemed universally intuitive. While domain-specific intuitions of experts are typically reliable, the domain of analytic metaphysics is essentially vacant. Concepts like p-zombies have not been encountered in a manner that would allow for expert analysis, leading Humphreys to sarcastically challenge metaphysicians:

“I place little credence in appeals to intuitions and so I pose this challenge to the ontologists who use them. How do you train philosophers to improve their intuitions and how can we recognize when you have been successful? What lies behind the Doctor of Intuition diploma on the metaphysician’s mental wall?” (p. 62)

Section 2.1: Issues with Conceptual Analysis

While conceptual analysis can be beneficial in philosophy of language, where it helps clarify how terms are used, its application in metaphysics is fraught with challenges. Metaphysicians often grapple with concepts that lack stable common-sense understanding, making the analysis subjective and prone to imprecision. This leads to the type of unproductive exchanges familiar to those who attend philosophy colloquia (p. 62).

Section 2.2: The Misunderstanding of Scale Invariance

Scale invariance suggests that properties remain constant regardless of the scale of observation. Whether the world exhibits scale invariance is an empirical question to be answered by science, which has shown that it does not. This assertion has significant implications for various metaphysical debates.

For example, much discussion in analytic metaphysics has assumed the equivalency "water = H2O." However, Humphreys points out that this equivalency is misleading. The left side refers to the macroscopic description of a liquid, while the right side describes individual molecules. The accurate equivalency is "water = a macroscopic collection of H2O molecules interacting in such a way that the properties of liquidity, transparency, and phase transitions are present." These properties are not observed at the molecular level.

Humphreys emphasizes that since human intuitions about ontology derive from experiences with human-sized entities, any inferences to realms beyond that domain carry significant inductive risk. Given the substantial evidence that such risks are high and that similar inferences have often led to erroneous conclusions, he recommends avoiding generalizations from intuitions in speculative ontology (p. 70).

So, what should metaphysicians do? They should engage with the philosophy of science. This approach ensures that metaphysicians remain closely connected to empirical findings. In contrast, the intuitions of speculative ontologists have long been outpaced by modern scientific discoveries, particularly in fundamental physics.

Why not abandon metaphysics altogether and leave it to scientists? Humphreys responds:

“Ordinary scientific practice is not oriented towards establishing claims [such as those, for instance] of realism or anti-realism. For the most part, when scientists try to do philosophy, they do it as amateurs, with noticeably poor results.” (p. 72)

In this video titled "Architecture and Objects with Graham Harman (Art after Nature 3)," Graham Harman delves into the interplay between architecture and objects, offering insights into how these elements shape our understanding of metaphysics.

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