In the literature the term “natural balance” occurs frequently and is used for highly divergent collections of facts and for results arrived at by different methods. In this paper it is attempted to give a review of the many possible meanings of “balance in nature”, and to evaluate the application of the term in the scientific literature.To achieve this twofold objective it seemed useful to start by giving as objective as possible a description of the “balance situation” in natural communities, (...) in analogy with the original physical concept and according to strict scientific criteria. On the basis of this working standard, part of the ecological literature is discussed with respect to statements and presumptions concerning “balance”. The extensive literature is classified according to several groups, on the one hand on the basis of the nature of the views , on the other hand according to the importance that certain authors attach to the theory of a given author. For each of these groups, an evaluation of the content of the term “balance” is given. It was found that the reasoning is not always sound and that the nature of the data on which the concept is based varies widely, which also holds for the method of reasoning applied in the conclusions drawn. In none of the publications arguments were found supporting the existence of a natural “balance situation” as formulated in the standard description. Consequently, it seemed justified to conclude that it is not correct to apply a concept “natural balance”, defined purely scientifically, to natural situations, either because “balance” in the indicated sense is simply not present or because the situation under consideration is not a natural one . The concept “natural balance” has had only heuristic value for scientific research. In other contexts it has a different value, because there criteria other than scientific or methodological ones hold for the content of a concept. It is therefore not objectionable to use the term “natural balance” in common parlance, especially since this usage makes it possible to convey to the layman a great deal in few words. (shrink)

The founding of the Carnegie Institute’s Department of Embryology in 1913, alongside its systematization of embryo staging, contributed to the mechanization of developmental stages of embryo growth in the early 20th century. For a brief period in the middle of the century, attention to the detailed interrelation between embryo development and time made pre-existing ideas about pregnancy ends less determinative of ideas about that developmental course. However, the turn to the genetic scale led to the disappearance of this attention, replaced (...) by a sense of biological life as seamlessly scripted. This study examines the history of what I refer to as temporal attention: attention to the live, unfolding potentialities within vital matter. The reintroduction of temporal attention to discussions of development allows us to more fully consider non-human vitality and the experiences of beings that house or otherwise intimately intersect with that vital tissue, regardless of outcomes. (shrink)