Through innovative calligraphy, the title can be read from right to left or vice-versa; Langdon calls this technique an ambigram. -- Source of annotation: Marvin or Ruth Sackner.

The word "philosphy" is presented as a reversal poem so that it reads the same when the print is turned upside down. Dom Sylvester Houedard, the British poet, also created poem reversals which could be read in a similar manner but the reversal created a new word(s). In Langdon's print, one aphorism reads "Philosophy may require looking at ideas from both sides." -- Source of annotation: Marvin or Ruth Sackner.

The reversal poems (ambigrams) in this book along with their documentation are by Langdon himself. These works are reminiscent of the reversal poems composed by Dom Sylvester Houedard. This second edition is expanded with 50 new ambigrams. -- Source of annotation: Marvin or Ruth Sackner.

The reversal poems in this book along with their documentation are by Langdon himself. -- Source of annotation: Marvin or Ruth Sackner.

Another contemporary poet who composed reversal poems was Dom Sylvester Houedard. -- Source of annotation: Marvin or Ruth Sackner.