Right, no text books that doesn’t cut it in the real world. Start quoting theorists and watch as the faithful roll their eyes and back away from the “consultant”. Back away from the expert nice and slow maybe no one will get hurt.
The best cliche answer goes to the old favorite. The manager works within the system while the leader works on the system. This has a wring of truth to it after all the system has to be defined, improved, smashed and rebirthed by someone. That would be the leader. The manager spends her time building efficient predictive models and improving efficiency, maximizing the value of the asset to the firm (phew I almost went MBA with that comment)
The manager utilizes scarce resources and available fixed assets to create value from process inputs. They maximize the value through efficiency and minimization of scrap and waste. They encourage the workforce to achieve goals that lead to targets and quotas being met.
The leader often has these same functional responsibilities. The difference lies not in achieving these for the leader is just as accountable as the manager but in the approach to the achievement. Challenging the status quo of a process, inspiring new innovative approaches and human behaviors, seeking new answers where others do not see a question, this is the playing field of the leader. The question for the leader is not how can I meet objectives, it is how can we redefine how we achieve our objectives and in doing so blow past them.
Lead (or manage) well