Is Causation Necessary?

Is Causation Necessary?

I don’t mean to be asking Hume’s question about the need for necessary connection in the causal relation; I mean to be asking whether causation (causal power) is a necessary feature of things. Granted that something has a causal power, does it necessarily have that power? Are its causal powers part of its essence? Kripke’s table is necessarily made of wood, given that it is actually made of wood, but does it necessarily have the causal powers it actually has? Are there possible worlds in which that table exists and lacks the causal powers it has in our world? Could it have the causal powers of a jellyfish instead, or a vacuum cleaner? Does it have no causal powers in some worlds? Some objects have zero causal powers (e.g., numbers), so could this table be like that in a possible world? Could the situation be reversed—numbers have causal powers in some worlds and tables don’t? Let’s agree that space and time as such have no causal powers as things actually are; could they nevertheless have causal powers in other possible worlds? Our physical universe has a wide range of causal powers, but could it (that universe) lack such powers? Is causality necessary or contingent to things? Is it like composition (necessary) or is it like spatial location (contingent)?

The first thing to be said about the answer to this question is that it is not clear. Our intuitions are not univocal on the matter. On the one hand, it seems imaginable that the very same object should exist and behave differently from the way it actually behaves, or not behave at all. The case is analogous to pain and C-fiber stimulation: we can apparently conceive of possible worlds in which C-fibers are correlated with another type of sensation, or with no sensation at all. C-fibers don’t dictate pain, don’t make it inevitable. Likewise, the shape and composition of an object seem contingently related to its causal profile—they don’t dictate what the object will do (as Hume famously argued). The one thing seems separable from the other. That very object could still exist even though it has had its causal powers stripped from it, as it could have its color and spatial location stripped from it. Causal powers are something superadded, conjoined, not something internal to its being the object it is. A type of causal dualism thus seems indicated: causal powers are something over and above other properties of the object like shape and composition (“distinct existences”, as Hume would say). But, on the other hand, such dualism offends our intuitive sense of unity in natural things: for how could the causal powers of an object transcend its actual properties—how could what it does float free of its actual make-up? So, our intuition of contingency (and hence causal dualism) must be mistaken; there must be a deep necessity at work here. Thus, the case resembles the mind-body problem in respect of modal questions: we are torn in opposite directions, subject to conflicting pressures. We are confronted by a deep metaphysical problem—the causation-body problem (where body here is understood as the totality of properties the object has sans its causal properties). We might even want to say that the causal is mysteriously connected to the non-causal; the connection is not pellucid, not even properly intelligible (by us). Maybe we don’t really know what causality is, or what ordinary properties are for that matter. We are intuiting in the dark, never a good place to intuit.

Let’s step back and try to get our bearings. How does causality fit into the grand scheme of things? Is it a necessary feature of the universe—this universe or any conceivable universe? Could God have created a causality-free universe—either one containing matter and mind or one made of very different materials? Certainly, some philosophers have been eliminative with respect to causality: it does not exist in the mind-independent world, nor in the mind itself. It is pure projection, sheer fantasy: the course of history is mere accidental sequence devoid of causal power (compare eliminative materialism). But even without such a radical anti-realist position, it seems conceivable that causation might someday disappear from the universe like a bad smell, rendering it static and unchanging. The connection between mass and gravity is notoriously lacking in perspicuity, so that the idea of massive objects with no gravitational causal powers appears perfectly intelligible. If we press the question, in virtue of what does matter have the causal powers we attribute to it, we come up empty handed; it seems brute, inexplicable. We are thus faced with the usual choice between three unpalatable alternatives: dualism, reductionism, or eliminationism. If causation is the “cement of the universe”, then it is an alarmingly elusive cement. We can’t even say whether Kripke’s table (which is nothing special) is necessarily combustible or stable or solid, though we know it actually has each of these attributes. We can’t say whether retaining these attributes is required for the table’s continued existence (or existence in a possible world). What looked like a local puzzle about tables and the like turns out to reflect a wider aporia about causation in general—about whether it is a real trait of the universe, or whether it is contingent to reality or necessary to it. The concept of reality, even concrete reality, does not logically imply causality—hence Platonism about numbers and epiphenomenalism about the mind.[1] Such anti-causal doctrines are not simply contradictory. But it is unclear whether material reality must be causally imbued: causality seems superadded to matter (extension, spatial occupancy), and yet it is hard to accept that just anything can be superadded—as if a table could act like a jellyfish! Could God have created the universe just as it is now and at the last minute decided not to add any causality to the mix? Could everything be just as it is except that it is all a causality-free zone? The causality-world problem is wide open and extremely confusing.[2]

[1] It would be useful to compile a list of all non-causal entities so as to see how they differ from causal entities, though the question is not without controversy. Thus: numbers, geometrical forms, space, time, colors, moral facts, qualia (?), spatial points, propositions (?), and infinities. Some would say that nothing has causal power save that injected by God’s will, counting themselves metaphysically sober; causation always comes from outside the object.

[2] What would we think if we came across a pebble on a beach that had none of the usual causal properties of pebbles despite its similarity to causally endowed pebbles? Would we put it in a museum and label it “The World’s Only Non-Causal Pebble”, as if it were just a natural curiosity?

6 replies
  1. Giulio Katis
    Giulio Katis says:

    Though individual things may not have necessary causal powers, I am not sure I can imagine a world in which there were no causal dependencies of some form (spatial, temporal, physical, logical, etc). Even in the case of mathematics, numbers say, I’d argue it is the case a mathematical object does have causal dependencies (logical, not physical) on others. There is no sense in which the number 3 can be said to exist independently of the number 1, or of some form of counting or addition operation.

    Could one logically consistently assert the following two statements: no thing can be said to have any essential, intrinsic or defining causal properties or powers; and all things are necessarily dependent causally on some other things?


Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.