Peter Ludlow (/ˈlʌdloʊ/; born January 16, 1957), who also writes under the pseudonyms Urizenus Sklar and EJ Spode, is an American philosopher.

In recent years Ludlow has written nonacademic essays on hacktivist culture and related phenomena such as WikiLeaks and the conceptual limits of blockchain technologies.

[2] In May 2015, Ludlow resigned his position at Northwestern after a university disciplinary body found that "he had engaged in sexual harassment involving two students.

"[3][4] The charges and their aftermath generated controversy and led to a book by the feminist author Laura Kipnis, who defended Ludlow.

He received his PhD in philosophy from Columbia University in 1985 under the direction of Charles Parsons, but also studied with Noam Chomsky and James Higginbotham at MIT.

[5] Ludlow's PhD dissertation defended a proposal dating back to the medieval logician Jean Buridan, and revived by W.V.O.

Quine in philosophy and James McCawley in linguistics, according to which so-called "intensional transitive verbs" like "seek" and "want" are really propositional attitudes in disguise.

Crucial to this account is the idea that the lexicon is dynamic and that speakers engaged in conversation will negotiate the coinage of terms "on the fly" in constructing attitude reports.

[8] In response to criticism from Jason Stanley in his book "Knowledge and Practical Interests", Ludlow has advanced a doctrine that he calls "Cheap Contextualism".

Ludlow has written a series of papers on the logical form of determiners (words like "all", "some", and "no") and has pursued the idea that their most interesting properties can be given purely formal or syntactic accounts.

The work borrows from one of the central ideas of medieval logic—the hypothesis that all the key logical inferences can be reduced down to just two basic inferences that are sensitive to whether the syntactic environment was dictum de omni or dictum de nullo—classical notions that are basically equivalent to the contemporary notions of upward and downward entailing environments.

Ludlow revives the medieval project by combining it with the descriptive tools of contemporary Chomskyan linguistics and recent technical work in formal logic.

In an e-book entitled "Our Future in Virtual Worlds" Ludlow argues that as our lives continue to move online, the Greek god model becomes ever more dangerous.

In a controversy, reported in the New York Times[11] and elsewhere (including law journals[12]), Ludlow was kicked out of The Sims Online after some editorials criticized Electronic Arts Corporation for their failures at managing and policing the gamespace.

[15] Ludlow has been a highly prominent, and sometimes controversial, figure in several virtual worlds communities, especially The Sims Online and Second Life, since the early 2000s.

Ludlow resigned from his position at Northwestern in November 2015 after a university disciplinary body found that he sexually assaulted two students.