Page 180, Footnote 36: there probably should have been a closing quote mark after ... exercises of humanity.

Page 327, Endnote [E31]: there is no marker in the text for this note.

Page 400, Minnesota, Minn.: as printed in the source document; probably an error for Minneapolis, Minn.

Page 464, Zenophon: the text consistently uses Xenophon.

Changes:

Illustrations and footnotes have been moved out of text paragraphs.

Some obvious minor typographical and punctuation errors have been corrected silently.

Table of Contents: Several page numbers have been corrected to the book’s actual page numbers.

Page 6, Endnote 1: closing quote mark inserted after ... principles of scientific education.

Page 13: closing quote mark inserted after ... be learned by doing them.