Abstract

J. Bigelow and R. Pargetter in their work Science and Necessity put forward a theory of the laws of nature as statements objectively different with respect to their modal qualification both from the laws of logic and from contingent truths. Contrary to the latter ones all laws are characterized by necessity. However, there are various kinds of necessity. The laws of logic are characterized by logical necessity, and the laws of nature - by natural necessity. The objective basis for differentiating modal qualification of statements belonging to the particular classes is that laws are truths about possibilities, also the ones that have not been actualized. The source of difference between logical and natural necessity is the differentiation between the range of possibilities described by respective laws. Hence, laws of nature prove to be - which is not mentioned by the authors - a posteriori necessary statements. The modal character has been the basis of the explanation of other considered properties of scientific laws: certain generality and the so-called range void