This book is valuable for the light it throws on Newman's astonishing mind. We used to be taught that there are two disciplines, Dogmatics and Apologetics. Dogmatics told you what to believe; Apologetics tried to persuade you that you could. The former is serious; the latter belongs to the Advert and Distribution Dept., and is a servile trade. Newman looked at this (though that isn't how Coulson puts it) and found it would not do: what to believe and how it can be believed are intertwined. So he pondered how man assents to anything (binomial theorem, fascism, the rules of chess . . .) and applied this to theology: hence the Grammar of Assent. Coulson has dug in the soil out of which this unique work grew (Newman's notebooks and manuscripts), and now we see why the Church authorities were alarmed. They weren't used to theology done this way. Yet Newman had respectable authority: St Thomas Aquinas. Whatever is received is received (said Thomas) 'according to the capacity of the receiver'; and so 'those in whom imagination, the cognitive faculty, and sense memory are better disposed are also better disposed for understanding' (S.Th., ia, 85.7). It sounds like subjectivism: asking 'how much will Jones swallow?'-which Ronald Knox made such fun of. But: No. St Thomas means that a gallon won't go into a pint pot; few infant brains can accomodate polysyllabic metaphysics. But that doesn't disprove metaphysics. Newman asks, 'how can you believe what you can't imagine?' Modes of ...