The essay begins with two vivid scenes—a battlefield and a celestial spectacle—to frame an inquiry into whether scientific advance will be humanity's liberator or undoing. It surveys contemporary science, arguing that research is unlikely to be halted by public opinion or economics, and examines shifts in emphasis from physics toward biology, the unsettled foundations of physical theory, and the social consequences of technological power. The author considers risks from destructive technologies, challenges of mechanization and unemployment, and the ethical and political questions raised by directed biological intervention, concluding that foresight and social organization are needed to steer scientific progress.