0. Peter L. has been peppering me with objections to bundle theories. This post considers the objection from change.
1. Distinguish existential change (coming into being and passing out of being) from alterational change, or alteration. Let us think about ordinary meso-particulars such as avocados and coffee cups. If an avocado is unripe on Monday but ripe on Friday, it has undergone alterational change: it has changed in respect of the property of being ripe. One and the same thing has become different in respect of one or more properties. (An avocado cannot ripen without becoming softer, tastier, etc.) Can a bundle theory make sense of an obvious instance of change such as this? It depends on what the bundle theory (BT) amounts to.
2. At a first approximation, a bundle theorist maintains that a thing is nothing more than a complex of properties contingently related by a bundling relation, Russellian compresence say. 'Nothing more' signals that on BT there is nothing in the thing that exemplifies the properties: there is no substratum (bare particular, thin particular) that supports and unifies them. This is not to say that on BT a thing is just its properties: it is obviously more, namely, these properties contingently bundled. A bundle is not a mathematical set, a mereological sum, or a conjunction of its properties. These entities exist 'automatically' given the existence of the properties. A bundle does not.
3. Properties are either universals or property-instance (tropes). For present purposes, BT is a bundle-of-universals theory. Accordingly, my avocado is a bundle of universals. Although a bundle is not a whole in the strict sense of classical mereology, it is a whole in an analogous sense, a sense sufficiently robust to be governed by a principle of extensionality: two bundles are the same iff they have all the same property-constituents. It follows that the unripe avocado on Monday cannot be numerically the same as the ripe avocado on Friday. And therein lies the rub. For they must be the same if it is the case that an alteration in the avocado has occurred.
So far, then, it appears that the bundle theory cannot accommodate alterational change. Such change, however, is a plain fact of experience. Ergo, the bundle theory in its first approximation is untenable.
4. This, objection, however, can be easily met by sophisticating the bundle theory and adopting a bundle-bundle theory. Call this BBT. Accordingly, a thing that persists over time such as an avocado is a diachronic bundle of synchronic or momentary bundles. The theory then has two stages. First, there is the construction of momentary bundles from universals. Then there is the construction of a diachronic bundle from these bundles. The momentary bundles have properties as constituents while the diachronic bundles do not have properties as constituents, but individuals. At both stages the bundling is contingent: the properties are contingently bundled to form momentary bundles and these resulting bundles are contingently bundled to form the persisting thing.
Accordingly, the unripe avocado is numerically the same as the ripe avocado in virtue of the fact that the earlier momentary bundles which have unripeness as a constituent are ontological parts of the same diachronic whole as the later momentary bundles which have ripeness as a constituent.
5. A sophisticated bundle theory does not, therefore, claim that a persisting thing is a bundle of properties; the claim is that a persisting thing is a bundle of individuals which are themselves bundles of properties. This disposes of the objection from change at least as formulated in #3 above.
6. BBT also allows us to accommodate the intuition that things have accidental properties. On the proto-theory BT according to which a persisting thing is a bundle of properties, it would seem that all properties must be essential, where an essential property is one a thing has in every possible world in which it exists. For if wholes have their parts essentially, and if bundles are wholes in this sense, and things are bundles of properties, then things have their properties essentially. But surely our avocado is not essentially ripe or unripe but accidentally one or the other. On BBT, however, it is a contingent fact that a momentary bundle MB1 having ripeness as a constituent is bundled with other momentary bundles. This implies that the diachronic bundle of bundles could have existed without MB1 and without other momentary bundles having ripeness as a constituent. It therefore seems to follow that BBT can accommodate accidental properties.
7. That is, BBT can accommodate the modal intuition that our avocado might never have been ripe. But what about the modal intuition that, given that the avocado is ripe at t, it might not have been ripe at t? This is a thornier question and the basis of a different objection that is is not defused by what I have said above. And so we reserve this objection for a separate post.
Leave a Reply