In one of the beginning chapters of the Le.M of Rav Nahman of Uman [I forget the number. I think it was around 14] is brought that what is left of a person in the next world is שכל הקנה Acquired Intellect. This concept he brings from The Guide for the Perplexed. What seems significant here is that not every subject that one studies contributes to his everlasting life. For example, how to become an expert at chess would not have anything to contribute to one's life in the World to Come. So just by simple reasoning we can see there is a difference between subjects. So study of how to become a decent person (Musar), we can understand contributes to one's everlasting salvation, since good character traits are not automatically acquired. One needs to pick up good character traits from parents or friends etc. There is no one that makes up their own value system out of thin air. They get it from TV, movies , Internet etc.
Another point is we can see learning the objective knowledge, knowledge that can be easily seen to be of the way God created the world, this knowledge can called the works of God. This object knowledge can be Physics or Mathematics or other aspects of Creation that are not man made knowledge, even though they needed to be discovered by Man.
