 Partly because of appealing formal features such as those mentioned so far, there is a long list of distinguished scholars advocating the firmness view of confirmation, from Keynes (1921) and Hosiasson-Lindenbaum (1940) onwards, most often coupled with some form of impermissive Bayesianism (see Hawthorne 2011 and Williamson 2011 for contemporary variations). In fact, \(F\)-confirmation fits most neatly a classical form of TE impermissivism à la Carnap, where one assumes that \(k = \top,\) that \(P\) is an “objective” initial probability based on essentially logical considerations, and that all the non-logical information available is collected in \(e\). The spirit of the Carnapian project never lost its appeal entirely (see, e.g., Festa 2003, Franklin 2001, Maher 2010, Paris 2011). However, the idea of a “logical” interpretation of \(P\) got stuck into difficulties that are often seen as insurmountable (e.g., Earman and Salmon 1992, 85–89; Gillies 2000, Ch. 3; Hájek 2019; Howson and Urbach 2006, 59–72; van Fraassen 1989, Ch. 12; Zabell 2011). And arguably, lacking some robust and effective impermissivist policy, the account of confirmation as firmness ends up loosing much of its philosophical momentum. The issues surrounding the ravens and blite paradoxes provide a useful illustration.