In vitro experimental approaches are of central importance to contemporary molecular and cellular biology and toxicology. However, the scientific value or impact of in vitro results depends on their relevance in vivo. In vitro effect studies address inobservable in vivo phenomena through experiments on analogous in vitro phenomena. We present a theoretical basis developed to evaluate the in vivo relevance of in vitro effect studies. As a case study, the procedure for measuring specific gene transcription in isolated cell nuclei (nuclear (...) run-off method) is analyzed It is concluded that current evidence fails to justify in vivo interpretations of nuclear run-off experiments within the framework of theoretical models of transcription, implying that quantitative in vivo interpretations are unwarranted. Qualitative interpretations of nuclear run-off experiments may be justified by inferring the best explanation, especially when significant in vitro effects follow in vivo perturbations.Elements of a general theory are proposed. It is concluded that quantitative in vivo interpretations are warranted primarily in biochemical quantitation of biomolecules, while studies on biological function should be interpreted qualitatively in terms of causal explanations. Inferences to the best explanations are strengthened through additional evidence and the creation of experimental differences (effects). (shrink)

Abstract During the last decades it has become widely accepted that scientific observations are ?theory?laden?. Scientists ?see? the world with their theories or theoretical presuppositions. In the present paper it is argued that they ?see? with their scientific instruments as well, as the uses of scientific instruments is an important characteristic of modern natural science. It is further argued that Euclidean geometry is intimately linked to technology, and hence that it plays a fundamental part in the construction and operation of (...) scientific instruments. Finally, Euclidean geometry is compared to fractal geometry, and the question of its a priori status is raised. Although the position that Euclidean geometry is a priori in the original Kantian sense is untenable, the paper concludes that in some restricted sense Euclidean geometry may be said to be a priori. (shrink)

Perhaps the most influential historian of science of the last century, Alexandre Koyré, famously argued that the icon of modern science, Galileo Galilei, was a Platonist who had hardly performed experiments. Koyré has been followed by other historians and philosophers of science. In addition, it is not difficult to find examples of Platonists in contemporary science, in particular in the physical sciences. A famous example is the icon of twenty century physics, Albert Einstein. This paper addresses two questions related to (...) the Platonism of modern physical science. The first is: How is Galileo’s Platonism compatible with the fact that he did perform experiments? The solution to this apparent paradox can be found in Plato’s late dialogue Timaeus. In the dialogue the world has been created by a divine craftsman according to an original plan. The task of the scientist is not primarily to describe the material world, but to reconstruct the original plan. This view has later been known as “God’s Eye View”. The second question is: If a God’s Eye View is unattainable, how is it possible to give a “rational reconstruction” of Galileo’s Platonism? The key-word is idealisation. It is further argued that idealisation is intimately related to technology. Technology is required to realize ideal experimental conditions, and the results are in its turn implemented in technology. The implication is that the quest for unity in science, based on physics as the basic science, should be replaced by the recognition of the diversity of the sciences. (shrink)

In a certain sense, uncertainty andignorance have been recognized in science andphilosophy from the time of the Greeks.However, the mathematical sciences have beendominated by the pursuit of certainty.Therefore, experiments under simplified andidealized conditions have been regarded as themost reliable source of knowledge. Normally,uncertainty could be ignored or controlled byapplying probability theory and statistics.Today, however, the situation is different.Uncertainty and ignorance have moved intofocus. In particular, the global character ofsome environmental problems has shown that theproblems cannot be disregarded. Therefore,scientists and technologists (...) have in many wayscome into a new situation. The Chernobylaccident is a dramatic example, however,problems such as a possible greenhouse effect,a possible reduction of the ozone layer, and soon are all of the same type. These encompasstotally different problems than scientists andtechnologists are traditionally trained to dealwith. In these cases, the standard use ofstatistics has to change, the burden of proofshould be reversed, one should draw ondifferent kinds of expertise, and, in general,science should be ``democratized.''. (shrink)