The ordinary view of causation
What do we
mean when we say that one thing “causes” another thing?
Our idea is
that of a making happen, a producing, or a bringing about. We mean that the one
thing made a change in another thing happen or brought it into
existence.
We think of
a cause as necessitating, forcing, oomphing its effect—so its effect must
occur.
We think of
causing as something akin to pushing or pulling, as exerting force.
We think of
causing as something that individual things do.
The man shattered the window.
The medication relieved the headache.
The sun heated the earth.
We think of
the individual things as having the power to make their effects happen.
A thing can cause only what is in its power to cause.
We think of
causation as asymmetrical, as having directionality.
A cause is responsible for its effect. An effect is not responsible for its cause.
We think of
some causes, i.e., persons, as producing their effects willingly.
We do not
suppose that these causings fall under “causal laws.” Or, we needn't suppose
that they do so to suppose or to know that they are causings.
Other
causes, we suppose, produce their effects naturally and by necessity.
An acorn, under the right conditions, develops into an oak tree.
The
important point here is that the core of our idea is not the idea of laws but
the idea of making happen. Laws are extrinsic to our ordinary notion of
causation.
About
causal laws: We do not think of causal laws as enforcing anything or as making
anything happen but merely as describing what certain things regularly do in
specified circumstances.
Rightly or
wrongly, this is our ordinarily notion.
Causation
so understood and explanation
We have
this idea of causation that is explanatory?
A thing
happens. Why did it happen?
A person
made it happen because he wanted something... he had power and motive,
or something
that regularly makes that sort of thing happen made it happen.
We have an
explanation of the thing in terms of powers and propensities.
The Humean
view of causation
Since David
Hume, a new conception of causation has been dominant.
An Inquiry, VII, Of the Idea of a Necessary Connection
Hume was an
empiricist. What's that?
He begins
with an empiricist principle:
"All our ideas are merely copies of our impressions, so it is impossible for us to think of anything that we haven’t previously felt through either our external or our internal senses."
When
“ideas” are confused, we can clear them up by looking to the impressions from
which they came.
Our “idea”
of causation is confused. Hume observes that the sense impression from which
our notion of causation is derived is not of one thing making another thing
happen, as might be thought, but simply of one event following upon another.
We do not
see causation in individual cases.
"When we look around us at external objects, and think about the operation of causes, we are never able to discover any power or necessary connection, any quality that ties the effect to the cause and makes it an infallible consequence of it. All we find is that the one does in fact follow the other. The impact of one billiard-ball is accompanied by motion in the other. This is all that appears to the outer senses. The mind feels no sentiment or inward impression from this sequence of events: so in no single particular instance of cause and effect is there anything that can suggest the idea of power or necessary connection."
“Making happen” is not observable.
"When we experience something for the first time, we never can conjecture what effect will result from it. But if the power or energy of any cause were discoverable by the mind, we would be able to foresee the effect even if we had no previous experience, and would be able straight off to say with confidence what the effect would be, simply through thought and reasoning."
We’re not
privy to any metaphysical connection, oomphing, behind scenes.
"The scenes of the universe are continually shifting, and one object follows another in an uninterrupted sequence; but the power or force that drives the whole machine is entirely concealed from us, and never shows itself in any of the sensible qualities of material things..."
Given what has been said…
"we are forced to conclude that we have no idea of ‘connection’ or ‘power’ at all, and that those words—as used in philosophical reasonings or in common life—have absolutely no meaning."
Perhaps the
idea comes from the constant conjunction of events such that events of one kind
are always associated and followed by events of another. Not so fast…
"But what can a number of instances contain that is different from any single instance that is supposed to be exactly like them? Only that when the mind experiences many similar instances, it acquires a habit of expectation: the repetition of the pattern affects it in such a way that when it observes an event of one of the two kinds it expects an event of the other kind to follow. So the feeling or impression from which we derive our idea of power or necessary connection is a feeling of connection in the mind—a feeling that accompanies the imagination’s habitual move from observing one event to expecting another of the kind that usually follows it. That’s all there is to it."
Hume offers
a set of definitions that do not go beyond experience.
(1) A cause is an event followed by another, where all events similar to the first are followed by events similar to the second.
(2) A cause is an event followed by another, where the appearance of the former always conveys the thought to the latter.
Humean
causation and explanation
Hume
delegitimized the notion of "making happen."
A causes B
when things of B’s sort regularly follow things of A’s sort.
Causation
is reduced to a pattern.
But then
causation seems to be non-explanatory.
Why do the
patterns exist at all? Why do the events happen?
Hume cannot
account for these things.
Scientific
explanation
Science
tells us the way that things happen in the world.
Science
provides us with a set of laws that describe the way in which things always or
tend to happen. It gives us patterns.
Knowledge
of these patterns is very useful.
We tend to
suppose that science tells us also why things happen—that is also explains what
happens. But does it?
What is
scientific explanation?
For a while
the covering law theory of scientific explanation dominated.
L is a law of nature that has been identified through scientific research. E is an an event or pattern of events. If it turns out that E instance of L, E is explained. To explain an event just is to show that it is expected given what we know about the laws of nature.
The
asymmetry problem: Explanation, like causation, is directional and
asymmetrical. A theory of explanation will have to explain the asymmetry of
explanation.
One can deduce the length of the shadow from the height of the flagpole and the position of the sun... Good
But one can also deduce the height of the flagpole from the length of the shadow and the position fo the sun.
And, moreover, one can deduce the position of the sun from the height of the flagpole and the length of the shadow.
The deduction can go any of these ways. But explanation does not. The height of the flagpole and length of the shadow do not explain the position of the sun.
It would seem that we need to introduce causation, an asymmetrical relation.
Attempts have been made to give an empirical theory of causation, i.e., one that does not involve anything that is unobservable.
Probability models
A was the cause of B just in case the occurrence of A raised the probability of B.
Counterfactual models
A was the cause of B just in case B would not have occurred had A not occurred.
I will here
ignore a host of difficulties and refinements related to these theories.
I mean to
bring out the point that at a theory of causation will have to explain the asymmetry of
causation... and neither of these proposals can do this.
Scientific
explanation and explanation
If the best
that science can do is describe the way that things happen, can it explain
anything?
Scientific
explanation is non-explanatory for the same reason that Humean causation is
non-explanatory.
Science
identifies causal laws and patterns of probability or dependence.
Events are
“explained” when they are situated within one of these patterns.
It does not
tell us why the patterns exist or why the events happen.
To get to
the why we’ll have to look outside of the sciences.
