Tanya (text based) Chapter 12 Class 3 (100).

Tanya Perek 12, Class 3 (100).
The מדריגת הבינוני works because he goes from מלוכה to ממשלה and back again (whenever he chooses to).
This is the first class on ממשלה.
The idea of מוח שליט על הלב is first of all שליט and מולך.
Secondly, it is the idea of בטבע- the nature (even of the Jewish) animal soul. This works (even from the טבע) because this Beinoni is such that even his nature is removed from sin.
This applies to us in those areas where we have no real נסיון.