Mereological Idealism

Abstract

According to common sense, some but not all collections of objects are unified into larger wholes. For instance, a certain collection of pieces composes a person’s desk, but there is no object composed of that person’s left ear and the Eiffel Tower. Mereological idealism is the view that our conceptualizing activity is responsible for this unification: a collection of objects composes a whole if and only if those objects are co-apprehended by some mind under some concept. This chapter develops this view in detail and defends it against objections. Additionally, the chapter argues that mereological idealism is able to solve certain well-known problems faced by other theories of composition: the vagueness problem, the causal exclusion problem, and the problem of alternative conceptual schemes.

Conceptualizing Kant’s Mereology

“…3. Kriegel (2012) and Pearce (2017) are exceptions. See Varzi (2016: §5) for a general overview where the focus is on vagueness.…”

“…(CJ 5:252) 25. For a more general discussion of this idea see Kriegel (2012) and Pearce (2017 In addition to making sense of decomposition, (MC 1 ) also sheds new light on the presupposition we encountered in the discussion of Thesis and Antithesis of the Second Antinomy. There I argued that Kant rejects the principle (Det) in favour of its negation:…”

Metaphysical idealism revisited

“…In fact, Pearce concedes that his mereological idealism is compatible with “content externalism”. (2017, p. 203) If externalism is true, then what is required for the existence of a composite object, say cloud, is not only the application of the concept < cloud > by a thinking being but also the underlying physical arrangement of molecules. In a similar vein, the mereological idealist can also concede the dependence of mental activity on microphysical events.…”

“…In a similar vein, the mereological idealist can also concede the dependence of mental activity on microphysical events. But in both cases, the physical reality to which a concept is to be applied, must be one “that can be described without reference to any composite objects.” (2017, p. 208) This brings a significant qualification, because then it is no longer just the mind's unifying power that is responsible for the existence of composite objects, the simple external entities lying out there play a role too.…”

“…So, mereological idealism is not a constitutive view, as it does not assert that all of fundamental reality is mental. Since mereological idealism is “neutral regarding the nature of fundamental reality” (2017, p. 202), the possibility that fundamental reality might still be physical does not by itself constitute an objection against Pearce. The problem arises when Pearce tries to distance the view from mereological universalism, “the view that any arbitrary collection of objects composes a whole.” (2017, p. 204) I take the “whole” here to mean real composite existent.…”