A heatmap displays pairwise distances between thirteen philosophy subfields, using a color gradient from pale yellow to deep blue to indicate similarity. The matrix is symmetrical, with each subfield listed along both axes and a dark diagonal representing zero distance. The visualization uses D3.js version 3.5.6, employing scales and SVG rectangles to render the grid. Data comes from a JavaScript file containing precomputed distance values, and the layout includes rotated text labels and a linear color legend.