This is an impressive book. It is a collection of all of the "I answer that" sections of the Summa Theologica. This gives you a supreme one-volume version of Thomas' affirmative thought on Catholic Theology and Philosophy. This is a great "Thumbnail" and "introduction" to the hefty five-volume opus that many people love, but few have read.
There are only two deficiencies with this volume. It does not have any commentary that other Thomistic books have, such as "A Summa of the Summa." Secondly, it omits the rather fascinating interplay of ideas that characterizes all of Thomas' works. Aquinas was agile at confronting and assimilating opposing ideas. He was able to intellectually met steel to steel, and this is what makes him a mental giant.
This book is good for Catholics who want to know their religion, or anyone who is not Catholic (as I am), who can appreciate a genius when he or she works