<p>In this third installment of a four part series on Thomas Kuhn and the allegedly incommensurable revolutions of science, I look at the idea of <em>epistemic</em> incommensurability. Last episode, I looked at <em>semantic</em> incommensurability - a more intuitively easier idea to get your head around. <em>Semantic</em> incommensurability is the idea that a shift in intensional meanings of a concept such as 'planet' or 'bile' can lead to that concept being untranslatable in terms of it’s former variations within older scientific paradigms so that an idea of progress in moving from one variation of a concept to the next becomes unintelligible. In this episode, I want to look at the idea of <em>epistemic</em> incommensurability where a shift in the intensional meanings of a concept and it's connected theory can produce two people to have two different experiences when viewing the same object or phenomenon. You see phlogiston; I see oxygen. We will see how our sweet eyes deceive us. Or so says Kuhn.</p>