THE question whether there is such a thing as a falsifiable singular statement (or a 'basic statement') will be examined later. Here I shall assume a positive answer to this question; and I shall examine how far my criterion of demarcation is applicable to theoretical systems-- if it is applicable at all. A critical discussion of a position usually called 'conventionalism' will raise first some problems of method, to be met by taking certain methodological decisions. Next I shall try to characterize the logical properties of those systems of theories which are fasifiable--falsifiable, that is, if our methodological decisions are adopted.
Objections are bound to be raised against my proposal to adopt falsifiability as our criterion for deciding whether or not a theoretical system belongs to empirical science. They will be raised, for example, by those who are influenced by the school of thought known as 'conventionalism'.1 Some of these objections have already been touched upon in sections 6, 11, and 17; they will now be considered a little more closely.____________________