Full Idea
To be an empiricist is to withhold belief in anything that goes beyond the actual, observable phenomena, and to recognise no objective modality in nature.
Gist of Idea
Empiricists deny what is unobservable, and reject objective modality
Source
Bas C. van Fraassen (The Scientific Image [1980], p.202), quoted by J Ladyman / D Ross - Every Thing Must Go 2.3.1
Book Reference
Ladyman,J/Ross,D: 'Every Thing Must Go' [OUP 2007], p.99
A Reaction
To only believe in what is actually observable strikes me as ridiculous. It might be, though, that we observe modality, in observing dispositions. If you pull back a bowstring, you feel the possibilities.