They should have, especially if you took psych 1 or whatever intro class your school offers. Thats where you learn the difference between the two, when and where the split happened, Tabula rasa/blank slate, etc.
You have to understand, body-mind philosophies stem from a religous belief...even though some of Descartes writings would have been considered blasphemy in those times. The mind being an extension of the body puts into perspective the thought that a "soul" does indeed exist.
The soul comes into the picture when there is a distinction between the mind/thoughts and the being that these transient thoughts,opinions,moods, etc are occuring to. In the "spiritual" world, the mind is still part of the external world while the Self is timeless and infinite.