We tend to prefer those theories of which we know (or suspect) that they

are closer to truth. The relation of having greater or lesser closeness-to-truth

(verisimilitude, truthlikeness) can therefore be interpreted as a preference rela-

tion and investigated within the context of the rich research about ‘combinative

preferences’ and preference logic. The general concept of verisimilitude has been

studied extensively over the course of the past fifty years. So far, however, this

research programme has rarely examined the logical properties of the relation

‘closer to truth’, and a general logic of truthlikeness is still lacking. Our present

work constitutes a step towards such a logic. We focus on a particular ‘question-

relative’ relation of comparative verisimilitude that is defined in terms of how

well the competing theories address a set of underlying questions. We show

that verisimilitude has logical properties that are very much different from those

of other preference-relations, such as relations of plausibility, or of comparative

possibility. Nonetheless, verisimilitude does also satisfy a number of interesting

axioms and properties that are shared by other preference-relations.