Recently published at Thomistica.net is an essay of mine, “Some Mistakes Due to What Is Per Accidens.” The essay discusses four philosophical mistakes when what is per accidens is taken to be what is actually per se to something. This logical error was discussed with lucidity by Dr. Duane Berquist in his lectures on logic, and hence I dedicate the essay to his memory. Any of the logical errors in the essay must be imputed, of course, to the author and not to the author’s teacher.