Someone defines leadership as follows: "Leadership can be defined as one's ability to get others to willingly follow." This is fine as far as it goes, but like most who think about leadership, David talks only about influencing people who report to the leader. Hence leadership influence is really meant to be applied downward. I think leadership can be shown upward and sideways as well whenever colleagues influence each other by showing a better way, which can be done either by example of by overtly promoting a new direction.

Another point worth thinking about is this: if leadership is genuinely an influence process, then how are we to classify decision making, such as when the person in charge makes a strategic decision? For me, this is management. Leadership must be restricted to influence. Otherwise we have no way of accounting for bottom-up leadership where the person showing it has no authority to decide for the people being influenced (led).

Interestingly, showing leadership upward doesn't require many of the qualities David talks about. You only need to be fair, for example, if you have responsibility for people. Leadership shown upwards works if the target audience is influenced and this can be done with a presentation of hard evidence if it is convincing enough. A technical geek with poor emotional intelligence might develop a new product, say an iPhone killer, and promote it to management in an aggressive or blunt manner but still show leadership if management buys his proposal.