Heifetz integrates "great man/great woman" (trait) theories of leadership with "great times" (situational) theories, and defines "leadership" as "an activity that fosters adaptive work and addresses the value conflicts that people hold." He distinguishes "technical" problems that may not require leadership (adaptive work) from "adaptive problems" which people experience as threatening to themselves or their group. (The conflict over abortion, for instance, can be seen as an adaptive problem, because it represents a value conflict that provokes work-avoidance--scapegoating, dishonesty, polarizing conversations, etc.)
Heifetz sees leadership as being "practical" and "authentic", and the leader is always working towards using authority (formal and informal) to help members of contesting groups arrive at solutions that promote fundamental values (such as democracy, equality before the law, freedom).
This book is not a "how-to" book and does not promote charismatic leadership (which the author would view as largely work-avoidance and dependency-fostering). Heifetz is an excellent writer and communicates well with both academics and interested citizens.
The author's writing is very clear.
I most liked his simple phrasing of complex issues; how the threads through the incomplete theories of leadership (Carlyle, James MacGregor Burns); his practical orientation; his emphasis on followers' responsibility; his way of describing how leadership fails; and his notions of leadership succession. I also liked that this is not a "how to do" leadership book (the "ten best ways to be a leader" genre) aimed at a particular audience (business leaders, educational leaders), but, instead, is a thought-provoking discussion of ideas about leadership.