Benjamin L.W. Sobel, Elements of Style: Copyright, Similarity, and Generative AI, 38 Harv. J. L. & Tech. 49 (2024).
Abstract
“You can’t copyright style” is a shibboleth in today’s debate over generative AI. This slogan is, at best, meaningless. More likely, it’s wrong. Sometimes, what we call “style” is copyrightable. “Substantial similarity” is the doctrine that assesses when stylistic copying becomes infringement, but it is notoriously erratic, and judges find it especially hard to apply to images. Current law obfuscates artists’ rights to control their works and the public’s rights to use generative AI trained on these works.
Part II explains how image-generating AI works and debunks the prominent metaphor that it is a “collage machine.” The metaphor erroneously posits that it is possible to differentiate “mechanical” reproductions of works of visual art from “intellectual” reproductions, and it erroneously implies that the distinction has legal significance. Generative AI is clearly learning to reproduce something from its training data: what matters is what that something is.
Part III defines style as a holistic attribute of a work, or a group of works, that comprises a constellation of expressive choices. These expressive choices might be unprotectable individually, but in combination, they may constitute protectable expression. Protectable style is not necessarily limited to expression in one discrete “work,” either: courts regularly find copyrightable expression in aggregations of multiple works.
Part III documents courts’ struggles to assess the scope of copyright protection in visual art and attributes these struggles to the substantial similarity test’s near-irreconcilable demands: courts must simultaneously dissect images into their constituent elements — a task judges claim they are unable to do — while also assessing works’ aesthetic appeal holistically and intuitively. Style has always been a challenge for substantial similarity because it is the form of expression least susceptible to analytical dissection and most likely to elicit inarticulate aesthetic intuitions. Generative AI models’ replication of style is a hard problem for copyright law because the models are purpose-built to identify and reproduce precisely the forms of similarity that are hardest to analyze legally.
