You can't judge a book by its covers.  We don't know which sacred geometry to believe.  But you can't blame the publishers for tapping different markets.  From Transpersonal Psychologies, edited by Charles Tart.

INSTRUCTIONS: Click to remove the endpaper design.

We came for the constructive symbology and stayed for the "certain other things."  From Rosicrvcian Symbology by George Winslow Plummer, 1916.

INSTRUCTIONS: Click to shift to the cover of a different book.

INSTRUCTIONS: Click to shift to page 124. From A Choice of Magic by Ruth Manning-Sanders and illustrated by Robin Jacques.

From Tri-State University's 1979 yearbook.

INSTRUCTIONS: Click to shift to page 153.

From I Am Not a Practicing Angel by Alta, 1975.

From Dialogue with Myself by Martin Cyril D'Arcy.

INSTRUCTIONS: Click to shift to the title page. From Flesh & Spirit by George Coulson, 1876.

Seems like an awfully large coffin for a mask, but you've heard of the "My tragedy is bigger than your tragedy" game.  From The Death of Tragedy by George Steiner.

From Our Little Egyptian Cousin, written and illustrated by Blanche McManus, 1908.

INSTRUCTIONS: Click to shift to the cover. From The Little Green God by Caroline Atwater Mason, 1902.

INSTRUCTIONS: Click to shift to the title page. From The Wonderful Year by Nancy Barnes.

From The Outline of Everything by Hector B. Toogood, 1923.

INSTRUCTIONS: Click to flip to a mirror of the title page. From Hearts Are the Fields by Ellen Turngre.

From The Laxdale Saga, translated by Muriel Press.

Delightful and rare: The Unicorn with Silver Shoes by Ella Young and illustrated by Robert Lawson.

From An Alphabet of Old Friends by Walter Crane, 1909.

An ice-skating kitten.  From Twinkle Toes and His Magic Mittens by Laura Rountree Smith and illustrated by F. R. Morgan, 1919.