Non-Jewish methods for perfecting character traits

Q: Is it permissible to use methods from non-Jews for perfecting our character traits?
A: On the face of it, it is permissible to learn wisdom from non-Jews, such as physics and mathematics but not ethical matters or those relating to serving Hashem. We see, however, that our great Rabbis did not stop from taking good ideas from non-Jews in the area of perfecting character traits after verifying that they fit within the Torah's view. In the Gemara in Berachot (8b), Rabban Gamliel says: I admire the Persians for three things -- their modesty in eating, the bathroom (they had latrines in which the excrement falls along an incline, away from the person) and in relations. And in the Gemara in Sanhedrin (39b), Rabbi Yehoshua ben Levi points out a contradiction between two verses from the prophet Yechezkel. He says in one place (5:7): "And you did not perform the laws of the non-Jews who surround you" while he says in another place (11:12): "And you performed the laws of the non-Jews who surround you." He resolves the contradiction that we did not perform the good things they did, but you did perform the bad things they did. The book "Chovot Ha-Levavot" takes from Arab philosophers. The book "Cheshbon Ha-Nefesh" by Rabbi Menachem Mendel Lapin of Satnov – to whom Rabbi Yisrael Salanter wrote a glowing recommendation and which was learned in Lithunian Yeshivot – was based on a book by Benjamin Franklin. There were obviously changes, purifications and "conversion" of the ideas. The Rambam in Shemoneh Perakim (introduction to Pirkei Avot) takes from Aristotle and says: Accept truth from one who says it. We obviously do not say about Aristotle: Get yourself a Rav (Pirkei Avot 1:6, 16). But if he says something correct, it is permissible to take it from him. Based on this idea of the Rambam, the author of the "Torah Temimah," in his Torah commentary "Tosefet Beracha," collects twenty-four examples in the Torah, among our Sages and great Rabbis where we learn from non-Jews (Bemidbar 24:5). We therefore see that it is permissible to learn good things from non-Jews in this area. After all, Yitro taught Moshe Rabbenu how to organize the court system. But we need to check very carefully if these ideas fit with the Torah. People say that the Rambam "converted" Aristotle. He took part of Aristotle's teaching and threw some in the garbage. He upset everyone. The followers of Aristotle were angry because he threw some in the garbage and he upset the Jews because he took some. Therefore, not everyone can decide what is acceptable and what is not, but in theory it is possible.