Cause and Effect I

 

Philosophers continue to debate issues of causation. It is no longer so much a matter of "refuting Hume." Nowadays, it may be for many more a matter of "refuting Wesley Salmon." 

So I will say something today about philosopher of science Wesley Salmon (1925 - 2001), affiliated with  the University of Arizona early in his career, and the University of Pittsburgh later. 

Before Salmon turned his attention to the subject, philosophers of science had coagulated around the proposition that scientists don't actually use any idea of causation. Practicing scientists get along well enough with correlation, the thinking went, so the philosophers who write about what they do, can do likewise. 

But when Salmon delved into the thinking and writing of scientists, he didn't find that at all. He found causal claims to be ubiquitous, and a great concern with how any phenomenon under study, to use a Salmonesqe expression, "fits into the causal nexus" of the world. 

Salmon said that scientific thinking on causation is distinctively mechanical, and it depends on spatial continuity. In these respects, it may contrast with "common sense." So much the worse for the latter. 

Consider the humble gas pedal. An automobile owner who doesn't know the inner workings of a car may conclude empirically, "when I hold the gas pedal all the way down, the car will accelerate." He (the owner) has observed this principle at work many times. He will likely infer not just correlation but causation, "my pressure against the pedal causes the acceleration," and he will do so confidently without knowing the particular go of it.

In fact (at least as I understand it -- I absolve Salmon of any guilt if I get the example wrong), my pressure against the pedal is the beginning of a process.  The pedal will turn a pivot that will pull the throttle wire, increasing the air flow. Various sensors monitor the airflow, and inject fuel accordingly to maintain a fixed ratio of fuel to air. 

A scientist, or in this case an engineer, can draw unbroken lines within the space of the car showing the flow of momentum from foot to pivot, the flow of air to the engine, etc. This sort of continuity is part of what leaves a scientist satisfied that he has uncovered the mechanism.  

So: causation is a real fact (not an artifact of the way our minds grapple with the world) and scientists uncover this fact. Spatio-temporal continuity is one of the signs that they have uncovered a reality.That is Salmon's view of cause/effect relations, and the common-sense/science contrast, in a nutshell. 

In a sense, this is a return to Cartesian mechanics. Descartes insisted that there can be no action at a distance, action is all a matter of things pushing and pulling each other.

Newton made so bold as to posit action at a distance. The Earth pulls at the moon across a distance. Nothing pushes the moon around its orbit. It is pulled -- at a distance -- and is constantly falling, but constantly missing the surface of the earth in its fall.  Newton would have disputed Salmon's stress on continuity. 

I'm told that we can draw upon Einstein to bring Newton and Salmon into accord. But much in Salmon still feels like a return to Cartesian mechanics!

And Salmon restarted debates over cause and effect. As suggested above: it isn't just how you answer Hume now. It is how you answer Salmon. 

More later.