Any text search is best done inside the pdf files in Adobe Reader: the files are fully searchable.
You can also do the following:
- Look through the general table of contents.
- Look through the detailed table of contents at the beginning of each of the six volumes. The page entries are clickable in Adobe Reader.
- Use the subject indices or the name indices at the end of each volume. The page entries are clickable in Adobe Reader.
There is something thought-provoking on every page of the text - also in these sections.