Theory-laden observation and incommensurability

Abstract

In this Taper, I investigate the logical relation between two claims: (1) observations are theory-laden(1) and (2) there is no empirical common ground upon which to evaluate successive scientific theories that belong to different paradigms. I, first, construct an argument where (1) is the main premise and (2) is the conclusion. I argue that the term "theory-laden" has three distinct senses: semantic, psychological and epistemic. If 'theory-laden' is understood in either epistemic or psychological senses, then the conclusion becomes a claim about people. If incommensurability is to be a claim about theories, then 'theory-laden' in the main premise should be understood in the semantic sense. I, then, argue that there is a further distinction to be drawn between the absolute and relative senses of theory-laden. The relative sense of theory-laden allows observations that are relatively neutral between the theories under examination. I then conclude that the argument from theory-ladenness only shows that foundational empiricism is not a tenable philosophical position, but it fails to show that no empirical test can decide between successive theories that belong to different paradigms.