People self-motivate when you provide situations that combine structure with ability to be creative.

The Thinking Behind The Tweet

Situations of pure structure don't promote motivation; situations devoid of structure promote unfocused motivation; situations can be constructed to uncrush creativity.

Well-designed process can co-exist with creativity: well-designed process can breed creativity.

Business Contains Only 3 Things: People, Process, & Situations. 

Spirited Leaders design situations, providing the opportunity to maximize self-motivation. Designing situations: that's the path to motivated work performance.