This paper aims to draw attention to an important but underappreciated aspect of the instrumental value of freedom: its diagnostic value. This is the value freedom has insofar as it makes it possible for us to discover ourselves and improve ourselves in our capacity to make value judgements. Diagnostic value, I argue, has an important role to play in explaining the value we attach to freedom. Accordingly, this paper is aimed at elucidating this concept, examining its relevance to our lives, (...) and defending an account of how to measure the diagnostic value of opportunities and sets of opportunities. (shrink)