Peter Drucker (1909-2005)

Peter Ferdinand Drucker was an Austrian American management consultant, educator, and author, whose writings contributed to the philosophical and practical foundations of modern management theory. He was also a leader in the development of management education, and contributed to the popularization of the concepts known as management by objectives and self-control, and he has been described as "the champion of management as a serious discipline".

Quotes

So much of what we call management consists in making it difficult for people to work.

Leadership
In all recorded history there has not been one economist who has had to worry about where the next meal would come from.

Economics
There is nothing so useless as doing efficiently that which should not be done at all.
Management is doing things right; leadership is doing the right things.
Management by objectives works if you first think through your objectives. Ninety percent of the time you haven't.