
Scientists use concepts and principles that are partly specific for  their subject matter, but they also share part of them with colleagues  working in different fields. Compare the biological notion of a 'natural  kind' with the general notion of 'confirmation' of a hypothesis by  certain evidence. Or compare the physical principle of the 'conservation  of energy' and the general principle of 'the unity of science'.  Scientists agree that all such notions and principles aren't as crystal  clear as one might wish.
An important task of the philosophy of  the special sciences, such as philosophy of physics, of biology and of  economics, to mention only a few of the many flourishing examples, is  the clarification of such subject specific concepts and principles.  Similarly, an important task of 'general' philosophy of science is the  clarification of concepts like 'confirmation' and principles like 'the  unity of science'. It is evident that clarfication of concepts and  principles only makes sense if one tries to do justice, as much as  possible, to the actual use of these notions by scientists, without  however following this use slavishly. That is, occasionally a  philosopher may have good reasons for suggesting to scientists that they  should deviate from a standard use. Frequently, this amounts to a plea  for differentiation in order to stop debates at cross-purposes due to  the conflation of different meanings.
While the special volumes  of the series of Handbooks of the Philosophy of Science address topics  relative to a specific discipline, this general volume deals with focal  issues of a general nature.
After an editorial introduction about  the dominant method of clarifying concepts and principles in philosophy  of science, called explication, the first five chapters deal with the  following subjects. Laws, theories, and research programs as units of  empirical knowledge (Theo Kuipers), various past and contemporary  perspectives on explanation (Stathis Psillos), the evaluation of  theories in terms of their virtues (Ilkka Niiniluto), and the role of  experiments in the natural sciences, notably physics and biology (Allan  Franklin), and their role in the social sciences, notably economics  (Wenceslao Gonzalez).
In the subsequent three chapters there is  even more attention to various positions and methods that philosophers  of science and scientists may favor: ontological, epistemological, and  methodological positions (James Ladyman), reduction, integration, and  the unity of science as aims in the sciences and the humanities (William  Bechtel and Andrew Hamilton), and logical, historical and computational  approaches to the philosophy of science (Atocha Aliseda and Donald  Gillies).