It’s the difference between any two elements at any level. Domain, Issue, Concern, whatever. ‘People need to Pursue unless they need to Avoid’ works just as well as ‘People need to Physics unless they need to Psychology’.
That’s just how the model works. There’s not any one element creating conflict. Conflict comes from the relationship between elements.
If you want two magnets to stick together and they won’t because they are sitting six feet apart, the problem is not that one magnet is six feet to the left and it’s not that the other magnet is six feet to the right. The problem is that there are six feet between the magnets. The conflict (magnets won’t stick together) is a result of the the relationship (six feet of physical space) between the magnets.
But since this is an analogy for the mind, we’re not talking about magnets, and we’re not talking about physical space.