Chemistry Reference
In-Depth Information
than being reunited, typically those fields each follow their own paths because they
have developed distinctive disciplinary approaches, research goals, and conceptual
frameworks. Some focus on quantitative prediction as their major research goal, as
in computer modeling. Others are interested in explanation by, for instance, study-
ing the mechanism of chemical processes. Issues of classification, either of sub-
stances or of reactions, dominate many fields, whereas others look upon that from
the specific point of improving synthetic capacities. There are fields of chemistry
studying phenomena that probably do not occur outside the laboratory, as well as
fields that define their identity by certain areas of nature, like bio-, geo- and
astrochemistry, or of industrial application, such as pharmaceutical or polymer
chemistry. Further, a broad range of chemical fields transgress disciplinary bound-
aries and adopt ideas, aims, and methods from their neighboring sciences, like
physical chemistry and mathematical chemistry.
While such a kind of pluralism might discomfort the monist philosopher, it only
illustrates the manifold goals and uses of science. The fact that the actual science
pursues a variety of epistemic purposes, other than the so-called “truth of theories”,
in an undogmatic manner, makes it useful and flexible enough to address current
and newly emerging problems. Even if we zoom in and look closer at the concep-
tual apparatus of individual fields, pluralism shows up.
Hasok Chang (
2012
) has shown in much detail for three important episodes in
the history of chemistry - the Chemical Revolution, early electrochemistry, and the
development of atomic and constitutional chemistry - how pluralist competition
and interaction enabled the successful development of central concepts and theo-
retical approaches in chemistry. Rather than ending such competitions by electing a
winner, chemists have frequently elaborated on the competitors and turned them
into alternative models that are each tailored to specific aims and research ques-
tions. An almost arbitrary look into chemical textbooks reveals the obvious
(Schummer
1998a
). In inorganic chemistry, for instance, various theoretically
guided concepts or models of what acids and bases are, compete with each other,
such as those by Brønsted, Lewis, Pearson, and many others. Yet the competition is
not about who is right or wrong, but about where exactly which model is more
useful in explanations and predictions. Similar choices can be made between ligand
theory and crystal field theory in chemistry of complex compounds; between the
models of Freundlich, Langmuir, BET, etc. in adsorption theory; between collision
and transition state theory in chemical kinetics; between a huge range of equations
of state (from the simple ideal gas law, to the equations of van der Waals, Peng-
Robinson-Stryjek-Vera, and dozens more) in thermodynamics; between molecular
orbital, valence bond, and density functional theory in quantum chemistry, each
including a variety of specific models; etc.
The case of molecular structure might illustrate further how the pluralism of
models works in chemistry (Schummer
1998b
). Since the mid-nineteenth century
organic chemists have developed classical chemical structure theory that assigns to
each compound a molecular structure, based on its elemental composition and
chemical reaction properties. In this theory, a molecular structure is not simply a
spatial arrangement of atoms, but an arrangement of so-called functional groups
