The first 50 years of system dynamics established an introduction to the field, and have shown the promise of achieving a better understanding of complex systems in nature and human affairs. Now the field is on a plateau ready to launch the next thrust forward. We can better understand the present status of system dynamics by comparison to professions that developed earlier. We are now at about the same state of advancement that engineering was when MIT first opened its doors in 1865, or that medicine was in the late 1800s when the Johns Hopkins School of Medicine was established. We have yet as much to learn about high-order nonlinear feedback structures around us as those earlier professions have learned about their fields in the last 150 years. Now is time to plan how the next 50 years can start to close this huge knowledge gap. Like the early days in more mature professions, we do not yet have universities devoted to four- and six-year programs. Like them at the beginning, we do not have the equivalent programs of science and biology in grade school education to condition the public to the challenges and opportunities to better understand the dynamic world of nature, management, politics, environmental change, economics, and social stresses. Looking into the next 50 years, we see