Metaphysical presuppositions and scientific practices: Reductionism and organicism in cancer research

Abstract

Metaphysical presuppositions are important for guiding scientific practices and research. The success of twentieth‐century biology, for instance, is largely attributable to presupposing that complex biological processes are reducible to elementary components. However, some biologists have challenged the sufficiency of reductionism for investigating complex biological phenomena and have proposed alternative presuppositions like organicism. In this article, contemporary cancer research is used as a case study to explore the importance of metaphysical presuppositions for guiding research. The predominant paradigm directing cancer research is the somatic mutation theory, in which mutated genes are presumed to be ultimately responsible for explaining carcinogenesis. This reductionistic approach to cancer has been criticised recently, and an organistic approach has been proposed. The article concludes with a discussion of the reciprocal interaction of metaphysical presuppositions and scientific practices for investigating cancer's complex nature.

Acknowledgements

I thank especially Alfred I. Tauber, as well as James W. McAllister and two anonymous referees of International Studies in the Philosophy of Science, for their insightful comments on an earlier draft of the manuscript. I also thank C. Stephen Evans, Bruce Gordon, Robert Roberts and Margaret Tate for their helpful discussions. A version of this paper was delivered at the 43rd annual programme of the Boston Colloquium for Philosophy of Science, ‘From Practice to Engagement: Science Studies Addresses Heterogeneous Complexity’, Boston University, MA. Baylor University supported my research through a Summer Sabbatical award and a University Research Committee grant.

Notes

James A. Marcum is associate professor of philosophy at Baylor University in Waco, Texas.

Correspondence to: James Marcum, Department of Philosophy, P.O. Box 97273, Baylor University, Waco, TX 76798, U.S.A. Email: [email protected].

Genetic determinism is a type of reductionism in which biological processes are reduced to genes. The reduction may be epistemological (biological entities are explained in terms of genes), ontological (biological entities are considered to be fundamentally composed of genes) or methodological (biological entities are investigated materially in terms of genes). There are other types of reductionism prevalent in twentieth century biology, such as physicalism, in which biological processes are explained in terms of fundamental material elements and forces. I thank an anonymous referee of International Studies in the Philosophy of Science for pointing out the distinction between genetic determinism and physicalism. For further discussion of reductionism, see Marcum and Verschuuren (1986).

Expansion of genetic determinism refers to the addition of more genes to account for the process of carcinogenesis. Weinberg and colleagues did not abandon their reliance on reductionism, since they believed that the generation of cancer is ultimately examinable and explainable in terms of a limited set of mutated genes.

For Sonnenschein and Soto, organicism is an explanatory notion in which ‘the emergent and integrative phenomena could not be explained directly in terms of chemistry and physics’ but in terms of higher levels of organisation, especially at the tissue level (1999, 114). Thus, they argue that ‘cancercinogenesis is an emergent phenomenon resulting from abnormal tissue organization’ (Sonnenschein and Soto, 1999, 114). For a detailed discussion of the criteria for an organicistic position in terms of top‐down causation, emergent properties, and level‐specific laws, especially as it relates to twentieth century developmental biology, see Gilbert and Sarkar (2000). Another important non‐reductive approach to biology, especially to developmental and evolutionary biology, is the developmental systems theory or DST (Oyama, 1985; Sterelny and Griffiths, 1999; Oyama, Griffiths and Gray, 2001). DST proponents reject reductionism and standard dichotomies, such as between genes and environments and any quantitative relationship between them for determining a trait. Rather, according to DST, ‘A developmental system is a collection of interacting entities…[that] give rise to a reliably recurring life cycle: A set of interactants found in early ontogeny causally create conditions under which later developmental stages appear, and these later stages also create the interactants that will give rise to a new generation’ (Godfrey‐Smith, 2000, S325). I thank an anonymous referee of International Studies in the Philosophy of Science for directing my attention to the DST literature.

Sonnenschein and Soto argue that empirical evidence obtained from incommensurable experimental approaches cannot be integrated: ‘Data based on conflicting paradigms can seldom be reconciled. This is because when researchers, explicitly or implicitly, adopt opposite premises they design experiments addressing different questions’ (1999, 70). They then propose a ‘paradigm’ shift from the prevalent somatic mutation theory to their tissue organisation field theory to account for carcinogenesis (1999, 134–43). Although Sonnenschein and Soto do not reference Thomas Kuhn (1996 [1962]) explicitly, they do rely on his philosophy of science implicitly to articulate and defend their position.

Gleevec or signal transduction inhibitor (STI) 571 is an inhibitor that binds an enzyme, a tyrosine kinase, which is part of a specific cell‐signalling pathway involved in cell proliferation. However, as Julian Kim (2003) acknowledges, despite the success with this drug in terms of targeting pathway‐specific molecules many cancers may require several target‐specific drugs because of the complexity or the number of pathways involved in carcinogenesis. Consequently, although the pragmatic success of such drugs appears to vindicate reductionism it does not necessarily vitiate organicism. I thank an anonymous referee of International Studies in the Philosophy of Science for this insight.

Sonnenschein and Soto (1999) identify organicistic techniques with technology that maintains the positional information present within an organ or a tissue. Both Sonnenschein and Soto and Bissell and colleagues have developed tissue culture techniques to include this information in examining the nature of carcinogenesis.

Additional information

Notes on contributors

James A. Marcum

James A. Marcum is associate professor of philosophy at Baylor University in Waco, Texas. Correspondence to: James Marcum, Department of Philosophy, P.O. Box 97273, Baylor University, Waco, TX 76798, U.S.A. Email: [email protected].