This chapter presents a rationale for the value of photojournalism as a vital part of civic discourse. Photojournalists can be seen as a network of trusted witnesses, collectively providing testimony and evidence from a wide and varied set of situations. Photojournalists and documentary photographers thus operate in a network of relations that create an ecology and an economy of images, stories, narratives, evidence and viewpoints. Collectively, all the various outputs generate a network of connected and related discourses that amplify and complement each other, providing multiple viewpoints and interpretations of the human condition that can expand a society's ability to know itself. Journalism, documentary film, television, fiction and nonfiction writing, art, academic writing and reports from Non-governmental organizations all have their own internal network of similar trusted witnesses, and also interlock and interweave with each other, reinforcing each other in a complex web of evidence, associations, interpretations and analysis.