Uncertainty is a fact of life. You can never know enough to make perfect decisions. Understanding this helps us balance an awareness of our tendency towards overconfidence with an acceptance of our own fallibility. The book discusses two opposed models of school improvement: the deficit model (which assumes problems are someone's fault) and the surplus model (which assumes problems are unintended systemic flaws). By aligning ourselves to a surplus model we can create a system of Intelligent Accountability. The principles that make this possible are trust, accountability and fairness. While we thrive when trusted, unless someone cares about - and is holding us to account - for what we do, we're unlikely to be our best. Some teachers deserve more trust and require less scrutiny than others, but in order to satisfy the demands of equality we end up treating all teachers as equally untrustworthy. The more we trust teachers, the more autonomy they should be given. To pursue a system of fair inequality we must accept that autonomy must be earned.