Mechanisms Versus Causes in Biology and Medicine - Mechanism and Causality in Biology and Economics - page 19

neurobiology (Machamer et al. 2000 ; hereafter referred to as MDC). Others worked
on mechanisms in such fields as biochemistry and cell biology (Bechtel and
Richardson 1993 , 2010 ; Bechtel 2006 ), evolutionary theory (Barros 2008 ), medi-
cine (Thagard 1998 ; Moghaddam-Taaheri 2011 ), and the social sciences (e.g.,
Hedstr ¨ m 2005 ). Philosophers work to analyze the relation of this new work on
mechanisms to traditional topics in philosophy of science, such as explanation
(Bechtel and Abrahamsen 2005 ; Craver 2007 ) and causation, addressed in diverse
ways by Jim Bogen (e.g., 2004 , 2005 , 2008 ), Bill Bechtel and Carl Craver (e.g.,
Craver and Bechtel 2007 ; Craver 2007 , Ch. 3), Stuart Glennan ( 1996 , 2002 , 2010 ),
and Jim Woodward (e.g., 2002 ).
Biologists seek mechanisms for three reasons: explanation, prediction, and
control. In this chapter, I will argue that within the mechanistic sciences, such as
molecular biology and molecular medicine, the claim “C causes E” is impoverished
compared to the claim that “this mechanism produces this phenomenon.” Knowl-
edge of a mechanism in the biological sciences is usually more useful for explana-
tion, prediction, and control than merely being able to label something as a cause.
Furthermore, the new mechanists emphasize the importance of characterizing (and
recharacterizing as work proceeds) the phenomenon that the mechanism produces.
Such characterization is a rich description, providing guidance and constraints in
the search for the mechanism.
I proceed as follows. In Sect. 2 , I summarize one current view of biological
mechanisms, the MDC characterization of biological mechanisms. In Sect. 3 , I first
summarize what we said in the MDC paper about the relation of the analysis of
mechanism to an analysis of cause. Then, I expand it to conjecture what “C causes
E” might refer to, from the perspective of biological mechanisms. In Sect. 4 , I take
up the extension of the MDC account to medicine and illustrate the power and
complexities that the search for mechanisms plays in an example from medicine.
Medical researchers seek mechanisms not just to give explanations for disease
symptoms but also to predict the occurrence and severity of the disease and control
the outcome for the patient's benefit. We might say: “A mutation in the CFTR gene
causes cystic fibrosis.” But that is much too simple. To illustrate the usefulness of
knowledge of mechanisms, I trace the history of our understanding of the
mechanisms that account for, and therapies to treat, the disease of cystic fibrosis.
This example illustrates general features about the role of discovering mechanisms
for explanation, prediction, and control in fields with practical aims, such as
medical research.
2 The MDC Characterization of Mechanisms
A mechanism is sought to explain how a phenomenon is produced. Our team of
Machamer, Darden, and Craver characterized mechanisms in the following way: