mind, matter, meaning and information

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causation

A line of dominoes is set up, each standing on end, so that when the first is pushed over, it knocks down the second, it the third, and so on. Each domino has stored, potential energy, and when its stability is compromised, by an input of energy from a finger or from the preceding domino, it falls down, transforming the potential energy to kinetic energy, some of which is transferred to the next in line, destabilising it in turn. Every occurrence of causation, of any kind, is accompanied by a movement of energy, and vice versa. And the falling of the last domino tells us that the first was pushed over—or at least that an earlier one fell—even if the beginning is out of sight of the end—so we have information flow too.

In communications theory, an information channel is defined as two sets of possible events—the input set and the output set—that are linked in terms of their probabilities. For instance, the Morse code for the letter “A” being keyed at one end of a telegraph circuit makes it likely that the same code will be sounded at the other end. You might think it more than merely likely, but there's always the possibility of a breakdown of some kind, and certainty is never absolute in any case. In this case, the input events are all the different Morse codes that might be keyed, and the output events are the same codes, sounded. Not all communications links are this simple: some will incorporate coding transformations such as “A” = “B”, “B” = “C”, for instance—but all conform to this principle, there is always some probability linkage. And causation can be viewed in exactly the same way: the occurrence of one event (the cause), makes the occurrence of another (the effect) more likely. Energy flow, information flow and causation are all basically the same thing. (See physical information.)

The flow of electricity is a bit like the row of falling dominoes, with electrons knocking and being knocked on from one atom to the next. Whether the electrical flow is used to transmit signals such as Morse code or power, it can be viewed as a causal chain.

Now, though, we come to the relationship between causation and levels of description or explanation. Let's dive in at the deep end and go straight to the relationship between mind and body. The ideas that our experience is determined by activity within the brain, and that a conscious effort of will can affect brain activity, are wrong for rather an interesting reason: both involve the concept of causation across levels of explanation.

We might call this “vertical” causation, unlike the common, horizontal sort by which, for instance, pressing a computer key causes a character to appear on the screen. Horizontal causation occurs on one level, and the concept is indispensable to our understanding of normal, everyday events. But to say that a certain pattern of neural excitation caused me to choose this particular word, is like saying that something becomes hot because its molecules vibrate more vigorously, when in fact its becoming hot is the increase in molecular vibration, and it became hot because it was left in the sun. I choose words because they seem appropriate at that point, not because certain neurons in my brain fire in a certain sequence. An explanation, generally speaking, must be on the same level as that which it claims to explain. (The “tipping point” phenomenon is sometimes cited as an example of vertical causation, but it is actually very similar to that of heating.)

When we move vertically, from one level to another above or below it, causation does not enter the picture. These are different ways of looking at the same thing, and so an explanation that starts on one level cannot continue on another—there is no temporal progression, essential in accounts of causation, in merely switching points of view—unless the move to be made is diagonal, having both horizontal and vertical components. For instance, muscle cell activity in my hands and arms might be considered to occur as a result of my decision to start typing. But the brain activity resulting in that of the muscles was not caused by the decision—it was the decision viewed at a lower level. Mental phenomena occur at a higher level than that of brain activity and there thus need be no interaction between them. Which is not to imply that there is no more to be said about this!

But to return to more familiar territory: The behaviour of a molecule is in a sense nothing more than the aggregated behaviour of its atoms. But for that very reason, it is wrong to consider molecular behaviour “driven” by the atomic sort. One thing cannot drive itself. We might find the appearance of such vertical causation where something happening at a small scale leads to much larger scale phenomena—for instance, where an infection initially involving only a small number of cells, and therefore discernable only using a microscope, results eventually in visible symptoms—but what we are in fact seeing is horizontal causation, in this case involving only cellular activity, aggregated up to the next level. I call this diagonal causation, but it should be noted that this is just a convenient expression, because true causation can only ever operate horizontally, along one level of explanation. We can certainly shift from one level to another, but that is a matter of translation, from one set of concepts to another, not causation. (And explanations involving heterogeneous sets of concepts are problematic at best.) Thus, just as it is invalid to claim that higher level entities are nothing but lower level ones, so it is wrong to say that higher level events are caused by lower level ones (or that lower level events are caused by higher level ones).

As is implied by the terminology of “levels of description” or “of explanation,” descriptions and explanations are level-specific. It is in the nature of such things to be of limited scope—to describe or explain something is necessarily to focus on that thing to the exclusion of other things, but rarely if ever are we dealing with a closed system, so something generally has to be omitted at the margin. Such margins are not just temporal and spatial, but occur also in the organisational hierarchy, such that we can only deal effectively with one level at a time. But the limitation in the case of causation is not (or not only) within ourselves, because one thing cannot be considered to cause what is actually the same thing seen from a different point of view, viewed at a higher or lower level. The concept of causation developed before that of levels of explanation, and the former is in fact not quite adequate in a worldview in which the latter are fully acknowledged.

(That there is a fairly fundamental problem with the concept of causation is evident when we try to account for the distinction between the cause of an event and other preconditions of it. Intuitively, the cause is “active” and other preconditions “passive,” but the only way to make sense of that is to suppose that when we make this distinction, we are projecting the concept of agency, derived from our own experience of acting, upon what seems to us the most important precondition. The active/passive distinction depends on where you're standing (or how fast and in which direction you're moving). There's nothing really special about an “active ingredient”.)

Where successive levels of explanation are metaphorically arrayed in the vertical dimension, causal explanations can extend only horizontally. Causation might sometimes appear to act vertically, but that is at most diagonal causation, which in turn is merely the horizontal variety with cause and effect viewed at different levels. But if chains of causation cannot really extend vertically or diagonally, and if phenomena on all levels are equally real, then the concept of causation must be equally valid on all levels. Events do not happen first on the lowest level, to be propagated up through the hierarchy to the highest ones—higher level events simply are lower level ones organised in particular patterns, so higher and lower level events occur simultaneously. Causation must in fact be considered to operate equally along every level of explanation.

We now have vertical correlation and horizontal causation, where the vertical dimension is that of levels of explanation, and time is horizontal. The correlation means that events on one level will tend to correspond to events on other levels, but the different causal explanations at different levels are independent, despite the correlation, and of equal validity.

It might be tempting to view these different levels of explanation as different aspects of the same “underlying” reality, but this is a misleading conception. They are different aspects, but not of any underlying reality—descriptions and explanations at different levels are not mere appearance but partial accounts of the whole truth, which encompasses what occurs at all levels. Patterns at all scales matter, in general terms. Events on two adjacent levels are correlated neither via some hidden medium, nor by any other causal factor, but by virtue of the way in which those at the lower level combine to constitute those at the higher level—and, equally, by virtue of the way in which events at the higher level can be disaggregated into lower level ones, because there is no good reason to give aggregation priority over disaggregation.

To weave information back into this story about causation and levels: a fairly obvious question is whether an objective abstraction could be causally effective. What we have to focus on here is that these are levels of description (static information) and explanation (dynamic information): informational functions with particular purposes. These are perfectly valid as far as they go, but no one of them could ever tell the whole story—even though it very likely will tell us all we need to know in some particular context.

If you have a problem with objective abstractions, you might insist that reality resides only at the very lowest level, but then you have to accept that, for even the most marginally practical purpose, it is forever beyond our ken. So, either way, higher level descriptions and explanations are all we “really” have. Different levels host alternative descriptions and explanations, and there is nothing to choose between them but applicability to the task in hand: on which level is it?

Objective abstractions are certainly causally effective in effect—because they function as such in our world view. (This would not convince a sceptic, but: for an example of a causally effective abstraction, consider money.) When you knocked your knee against the table leg, you experienced a simplification of an unimaginably large and complex set of interconnected subatomic events—and that aspect of reality should not be denied—but where does it take us? Outside of our ordinary world view, even causation itself comes into question (see above), and due to the sheer vertical “distance” between them, and the number of events involved at the lower levels, we certainly cannot and will not ever be able in practice to trace everyday events at the subatomic level. Objective abstractions are neither absolute reality nor mere appearance, because, as will become evident elsewhere, that dichotomy is just a little too naïve—this being one of the areas, like relativity theory and quantum mechanics, in which we see the breakdown of our ordinary view of reality.

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Copyright © 1998—2005 by Robin Faichney. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/). Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder. Distribution of the work or derivative of the work in any standard (paper) book form is prohibited unless prior permission is obtained from the copyright holder. Last modified 29-Mar-2005 20:17:38 by Robin Faichney .