Human beings are imperfect. Mistakes and errors happen. They are quickly overwhelmed by the complexity of the world. This makes them a security risk in organisations and at the same time a brilliant innovative force. How do we as leaders influence people's behaviour? How do we shape organisations in order to find a meaningful way of dealing with complexity? What leadership approaches are appropriate and what image of humanity is needed as a basic prerequisite? What psychological knowledge can help in dealing with ambiguity? How do these issues correlate with the security interests of an organisation?