Cogency,Warrant Transmission‐Increase and non‐Ideal Thinkers

Contemporary debates concerning warrant transmission take for granted this thesis: when warrant transmission fails the argument fails. I challenge this thesis. An argument with conclusion C, addressed to subject S, can be cogent in the sense that recognition that the premises entail (or make highly likely) C can rationally foster in S the belief in C, without the warrant for C necessarily being gained (or reinforced) by such recognition. A key idea is to accept that some arguments should be understood in a way that involves the abandonment of two characteristic idealizations imposed on rational thinkers by Bayesian modelling.