A study of sustainability needs to consider the role of all forms of capital—natural, biological, social, technological, financial, cultural—and the complex ways in which they interact. All forms of capital derive their value, utility and application from human mental awareness, creativity and social innovation. This makes human capital, including social capital, the central determinant of resource productivity and sustainability. Humanity has entered the Anthropocene Epoch in which human changes have become the predominant factor in evolution. Humanity is itself evolving from animal physicality to social vitality to mental individuality. This transition has profound bearing on human productive capabilities, adaptability, creativity and values, the organization of economy, public policy, social awareness and life styles that determine sustainability. This article examines the linkages between population, economic development, employment, education, health, social equity, cultural values, energy intensity and sustainability in the context of evolving human consciousness. It concludes that development of human capital is the critical determinant of long-term sustainability and that efforts to accelerate the evolution of human consciousness and emergence of mentally self-conscious individuals will be the most effective approach for ensuring a sustainable future. Education is the primary lever. Human choice matters.