on 21 November 1997
Mortimer Adler is often regarded as a superficial popularizer, but in this book (first published in 1976) he explores an important philosophical topic with all the rigor and depth one could ask for. Deliberately patterning himself after the "quaestio" form of St. Thomas Aquinas's Summa, he sets forth the questions to be answered in a logical order and answers them in a spare, rigorous style that is a joy to read. The theory expounded is too complex to be stated here, but it reasons from certain observed phenomena in the use of language to the postulation of certain unobservable entities, just as in science we reason from certain observations and measurements to the existence of (for instance) electrons. The theory has some difficulties, to be sure, but even if you don't find it convincing, you will find this a glowing example of how philosophy ought to be written.