Original papers Analytical chemistry; the science of many models*

Summary. We argue that physical reductionism is a one-sided view of science. While it has successfully guided detection of elementary building blocks in many domains of science, and reduction of different sciences to the elementary objects, properties and interactions in physics, it provides little help for other scientific activities and is particularly ill suited to describe analytical chemistry. Analytical chemistry focuses on (1) empirical meaning of chemical concepts and on (2) understanding the structure of any particular sample. The primary theoretical tool of analytical chemistry is (3) model construction. Considering that activities (1 - 3) are complementary to formation of reductionist theories, analytical chemistry is as much in the forefront of research as theoretical physics, expanding our knowledge in other, equally indispensable directions. In this paper we briefly describe (1) and (2), and then we concentrate on model formation and the role of models in science. Models combine knowledge of basic building blocks, knowledge of structure, and elements of empirical meaning. Models play an essential role in preparation for measurements and in developing new measurement procedures. They expand our capability for knowledge verification and systematization. They are critical in understanding the hidden structure of objects and processes and in identifying new phenomena. A model is a product of synthesis and describes structured objects and situations, usually complex, as combinations of basic elements. Basic elements are provided by reductionistic theories which are the product of knowledge analysis and describe simple elements of nature and their interaction viewed from a singular perspective of either gravity, or electromagnetism, thermal phenomena, and the like. Model construction, not theory construction, is a basic theoretical tool in domains such as chemistry, which study complex systems and phenomena. We analyse the process of model creation, pointing out that it oscillates between solvability of equations and adequacy of description. As an example we analyse model construction in the domain of ion selective electrodes.