- Critical Thinking, sixth edition: An Introduction to the Basic Skills
- ".As a means of improving their thinking it is more successful than anything I've tried.The exercises are excellent." -- Cleo Boyd, University of Toronto"This is a good book. Hughes' writing is always clear, and his approach is thoroughly sensible." -- David Detmer, Purdue University"a helpful text which is destined to make a noteworthy contribution to the critical thinking movement.