Life

A corollary of the philosophical contrast between mechanistic and holistic materialist conceptions of life is the distinction between reductionist and integrative methodologies. Reductionism, closely allied to mechanistic materialism, is the view that the proper way to study organisms is to take them apart and examine and characterize their individual components in isolation under strictly controlled external conditions. For example, to study the way in which the heart functions, a reductionist would remove the organ from the body and place it in a chamber where temperature, pH, and concentration of other ions could be held constant. Integrative biologists argue that the reductionist approach is a necessary if insufficient approach to understanding complex systems. The heart in the intact animal, they point out, is connected to nerves, blood vessels, and other organs and thus is subject to neural and hormonal influences that cannot be understood from investigation of the heart in an isolated chamber. According to proponents of holism, it is necessary to devise methods for studying component parts in the living state, in the context of the whole organism of which they are a part (in vivo), as opposed to studying them only as isolated entities (in vitro).

A component of the methodological debate between reductionism and holism is the debate between the strictly observational and the experimental approach to living systems. Proponents of strictly observational studies, such as the Austrian animal behaviorist Konrad Lorenz (1903–1989) from the 1930s to the 1960s, argue that living systems must be studied in their natural context and that when experimenters bring organisms into the laboratory under highly artificial (controlled) conditions, they create an environment so foreign to the organisms that the information obtained is an artifact and of limited use. In contrast, proponents of experimentation, such as the behaviorist Daniel Lehrman, point out that restricting investigations to only what can be observed under "natural" conditions limits the kinds of questions the investigator can ask and the kinds of information that he or she can obtain. Such debates have surfaced in fields such as ecology, evolution, and animal behavior, where field investigators have often claimed that laboratory conditions are so different from those the organisms experience in the wild that the information obtained can have little relevance to how the organism functions in its natural habitat. Experimentalists argue that those who limit their work strictly to field observation have no ways to test their theories and consequently can never develop a rigorous, scientific explanation. Of course as many scientists and philosophers have pointed out, the approaches, like those of reductionism and holism, are actually complementary. Nonetheless, debates on reductionism and holism, observation and experimentation, have continued to resurface and influence the development of biology down to the twenty-first century.