Amidst all of the important improvements in Environmental, Social and Governance (ESG) data, all of the thoughtful research reports, and all innovative new investment options, another, deeper trend has taken root. As we turn towards 2019, we see increasing evidence that Systems Thinking is becoming more prevalent and influential throughout corporations and the sustainable investment community. This subtle, under-the-surface development is one of the most vital requirements for effective long-term investing. Systems Thinking aims to understand the whole, in addition to the individual parts.