In ‘Semantic Foundations for the Logic of Preference’ (Rescher, ed.,The Logic of Decision and Action, University Press, Pittsburgh, 1967), Nicholas Rescher claims that, on the semantics developed in that paper, a certain principle - call it ‘Q’ turns out to be ‘unacceptable’. I argue, however, that, given certain assumptions that Rescher invokes in that same paper,Q can in fact be shown to be a ‘preference-tautology’, and henceQ should be classified as ‘acceptable’ on Rescher's theory.

Graphical AbstractIdentifying the properties and molecules of the intestinal microbiome may help our understanding of various diseases and therefore facilitate their treatment; from excluding pathogens to manipulation of the immune system and regulation of non-intestinal sites.