This document discusses systems thinking and causal loop diagrams. It provides examples of causal loop diagrams mapping the relationships between donations, fundraising, revenue, and staffing for a nonprofit organization. The diagrams show reinforcing loops, where increases/decreases in one variable lead to same-direction changes in connected variables, and balancing loops, where changes in one variable lead to opposite changes in others. The document encourages readers to identify leverage points and test interventions using their causal loop diagram models.