Torah im Derech Eretz (English Wikipedia)

Professor Levi points out, however, that Rabbi Hirsch was required to make the speech for "political reasons" and that in this speech Hirsch "did not even hint, not a single word, that the Jewish people had anything at all to learn from [Schiller's] ideas." See הרש"ר הירש כמורה דרך לדורנו (Rabbi Samson Raphael Hirsch as a guide for our generation), section: יהדות על טהרת הקודש

e-daf.com

Rothstein, Gidon, "Maharal on Avot", RJConline.org, archived from the original on 2010-10-31.

Taubes, M, The value of work, The Practical Torah, Tzemach Dovid, archived from the original on 2012-10-14.

Rothstein, Gidon, "Maharal on Avot", RJConline.org, archived from the original on 2010-10-31.
Taubes, M, The value of work, The Practical Torah, Tzemach Dovid, archived from the original on 2012-10-14.
See for example Menachem Schneerson, Insights Into Pirkei Avos Archived 2007-09-10 at the Wayback Machine
In fact, as of 2008 there has been some conflict between leading members of the community as to which direction it should take: see under Khal Adath Jeshurun (Washington Heights, Manhattan) and Controversial Moments At Rav S.R. Hirsch Memorial Celebration, Article by Elliot Resnick, The Jewish Press, Friday, June 27, 2008, p. 18 Archived June 30, 2008, at the Wayback Machine

Mishna Berurah on simanim 155 and 156
Kiddushin Mishna 4:14
Rema on Shulkhan Arukh, Yoreh De'ah 246:21
e.g., Shulchan Aruch: Yoreh Deah siman 246, Orach Chayim siman 156; Mishneh Torah: Deot Ch.5, Talmud Torah Ch.3
Moshe Isserles (Rema) on Yoreh Deah siman 246:4 allows study of שאר החכמות (wisdom), but limits this such that: this study is באקראי (non-fixed, as required, secondary to Torah); and excludes study of ספרי מינים ("heretical works").

Moshe Isserles (Rema) on Yoreh Deah siman 246:4 allows study of שאר החכמות (wisdom), but limits this such that: this study is באקראי (non-fixed, as required, secondary to Torah); and excludes study of ספרי מינים ("heretical works").