1. A system for arranging concept clusters in thematic neighborhood relationships in a shaped two-dimensional visual display space, comprising: a clustering module to select a set of clusters from a concept space comprising a multiplicity of clusters with concepts extracted to visualize document content; a theme generator to identify a theme in each of a plurality of the clusters, each theme comprising at least one such concept ranked within the cluster; a spine placement module to logically form a plurality of unique candidate spines comprising clusters sharing at least one common theme and assigning one or more of the clusters to one such candidate spine having a substantially best fit, and to identify each best fit candidate spine sufficiently unique from each other such best fit candidate spine and placing the identified best fit candidate spine in a visual display space; and a spine group placement module to evaluate a similarity between each non-identified best fit candidate spine and each placed best fit candidate spine and to place each non-identified best fit candidate spine in the visual display space relative to an anchor cluster on the placed best fit candidate spine that is sufficiently similar to the non-identified best fit candidate spine.