Rav Nahman did not hold with learning philosophy nor any secular studies. He echoed Rav Hai Gaon. But this was not the approach of Ibn Pakuda and Rambam. I went with the approach of Rav Nahman for a few years and yet my experiences with the more or less ghetto [frum] ultra religious world gave me reason to  reconsider. And so with due respect to Rav Nahman, I tend to the approach of Ibn Pakuda, Rambam and Gra who all held from the importance of some secular disciplines - but with a lot of limitations. In the long run, I have to conclude that certain philosophers of the ancient Greeks are important, and Kant also. The natural sciences also. However psychology is pseudo  science. See Karl Popper for the reason.

[In the approach of the Rambam, physics and metaphysics are apart of the mitzvah to learn Gemara. in laws of learning Torah where he says divide the learning into three parts--written law, oral law, gemara. and the subjects brought in the first four chapters are in the category of gemara.]