Mechanisms Versus Causes in Biology and Medicine - Mechanism and Causality in Biology and Economics - page 23

3 Mechanisms and Causes
In this section, I briefly discuss ways that talk of “cause” and “effect” may possibly
be mapped to talk of “mechanism” and “phenomenon.” This is not a thorough
discussion of the many topics addressed by those analyzing causation. Rather it is
just a brief foray, from the perspective of some of the recent work on biological
mechanisms, to show how much more impoverished talk of “causes” is compared to
talk of “mechanisms.”
Possible referents of the term “cause” are many and varied from the mechanistic
perspective. Something that is designated as a cause may refer to a piece of a
mechanism. MDC analyzed mechanisms as composed of both entities (with their
properties) and activities. Activities are producers of change; they are constitutive
of the transformations that yield new states of affairs. As Machamer ( 2004 ) noted,
activities are often referred to by verbs or verb forms (e.g., participles, gerunds).
Molecules bond , helices unwind , ion channels open , and chromosomes pair and
separate .
In MDC, we discussed the relation between cause and activity:
Activities are types of causes. Terms like “cause” and “interact” are abstract terms that need
to be specified with a type of activity and are often so specified in typical scientific
discourse. (MDC 2000 ,p.6)
We followed Elizabeth Anscombe ( 1971 , p. l37), who noted that the word
“cause” itself is highly general. It needs to be specified by other, more specific,
causal verbs. Anscombe included the following in her list: scrape, push, dry, carry,
eat, burn, and knock over.
Activities are one way to specify causes. An important feature of activities is that
they come in types that have been discovered as science has changed. Over the
centuries, scientists discovered new types of activities and their ways of operating.
Once they are discovered and their modes of operating well understood, types of
activities become part of the “store” or “library” of mechanism parts used to
construct mechanistic hypotheses in a particular biological field (Darden 2001 ;
Craver and Darden 2001 ). The kinds of activities most important in molecular
biological mechanisms are, first, the push/pull geometrico-mechanical activities
familiar since the beginning of the seventeenth-century mechanical worldview and,
second, the many forms of chemical bonding discovered in the nineteenth and early
twentieth centuries. Each field finds the activities that drive its mechanisms.
A major advantage of the MDC view of causes as types of activities is that the
vague term “cause” must be made more specific. The specific way that a specific
change is brought about must be found in order to have an adequate description of
a mechanism.
Methodologically, activities can sometimes be identified independently of the
specific entities that engage in them. For example, the melting temperature of
the DNA double helix indicated that it contained weak hydrogen bonds, even before
the specific subcomponents (the DNA bases) exhibiting those bonds had been
identified. More generally, activities may sometimes be investigated to find their