The Co-Citation Network for Philosophy is a sprawling graph which demonstrates trends (rather than absolutes) in citation between publications in top journals. The image below shows the complete graph. Any point on this graph can be dragged out of the way to reveal overlapping text and possibly freeze your browser.
A user unfamiliar with the field of philosophy could reasonably expect to get some useful information out of this graph. Critically, for someone like me who has no idea who the key authors are in the field, this is a decent way to locate some of the trend-setting texts for introduction (although, in fairness, gives no suggestion on whether other, prerequisite texts might need to be read before them. For example, as the graph’s designer notes, David Lewis is frequently found at the center of citation clusters, marking him as a key figure in English-language philosophy.
On the opposite end of the spectrum, some clusters form isolated, operating as small, closed discussions (some overlap may still exist; the graph only manages relationships over a specified threshold of citations). These discussions, were I to speculate on them, likely represent authors who are part of particularly niche debates or overlap strongly with other, non-philosophy fields, thus preventing them from forming citation chains with authors in more central positions on the graph.
While useful, the graph has strong limitations. The creator notes that the project is not in a finished state and that it remains, at this time, primarily “descriptive” in nature. As such, more complex data must be sourced from elsewhere. This does not inherently render the graph useless for such efforts, though. For example, while the graph offers no data on items such as gender, race, or seniority, the most-cited authors are made very clear. Comparing them with data on these subjects gathered from other sources could create a fairly clear (if time-consuming) picture of the biases at play in English-language philosophy.