Reasons and reasoning were central to the work of Paul Grice, one of the most influential and admired philosophers of the late 20th century. In the John Locke Lectures that Grice delivered in Oxford at the end of the 1970s, he set out his fundamental thoughts about these topics; 'Aspects of Reason' is the publication of those lectures. In both the details and his grander visions, Grice presents us with many original ideas which will be of substantial interest independently of the use to which he puts them ... The issues it addresses are foundational to the philosophy of language and mind, and Grice's brilliance with ordinary language makes substantial advances towards the problems therein.