The primacy of the act of observation, one of the hallmarks of empiricism, found new life in the centrality of the distinction, made in Bas van Fraassen's constructive empiricism, between observable and unobservable. As Elliott Sober (and others) have pointed out, however, it is not clear what van Fraassen understands by observing an object. Worse, the Dutch philosopher does not seem to consider that a clarification of this point is necessary. This, of course, represents an important lacuna in a position generally considered as the main reference for modern empiricism. My goal is to take up again the counterfactual conditionals characterizing perception that Otávio Bueno presented in 2011 in this journal, and also to consider the observability and the existence criteria proposed by Filip Buekens and Michel Ghins, in order to get to a definition of observation that should give van Fraassen's observability concept the support it actually lacks, but without presenting itself as an ad hoc solution.
Observation; Perception; Observability; Relevant counterfactuals; Constructive empiricism; Van Fraassen; Buekens; Bueno; Ghins; Noë