In brief therapy, the therapist takes responsibility for working more pro-actively with the client in order to treat clinical and subjective conditions faster.
It also emphasizes precise observation, utilization of natural resources, and a temporary suspension of disbelief to consider new perspectives and multiple viewpoints.
Rather than the formal analysis of historical causes of distress, the primary approach of brief therapy is to help the client to view the present from a wider context and to utilize more functional understandings (not necessarily at a conscious level).
Brief therapists do not adhere to one "correct" approach, but rather accept that there being many paths, any of them may or may not, in combination, turn out to be ultimately beneficial.
His approach was popularized by Jay Haley, in the book Uncommon therapy: The psychiatric techniques of Milton Erickson M.D.