[3] Gotthelf published many articles and reviews in ancient philosophy and science, especially on the philosophical significance of Aristotle's scientific methodology and biology.

He joined the department of philosophy at Rutgers University as the Anthem Foundation Distinguished Fellow in the fall of 2012, where he taught until his death from cancer on August 30, 2013.

He attended many lecture courses and question periods at the Nathaniel Branden Institute, where he worked as an usher (and in other capacities), and where in 1962 he first met Ayn Rand.

It was suggestions from both Gotthelf and Leonard Peikoff which motivated Rand to write her extended monograph on concepts, Introduction to Objectivist Epistemology.

[9] Starting in 1964, he spoke on Rand's philosophy, Objectivism, countless times at colleges, universities, and private groups throughout the United States, Canada, Bermuda, Europe, and Japan.

[2][10] He was co-editor (also with Salmieri) of the forthcoming Wiley–Blackwell volume, Ayn Rand: A Companion to Her Works and Thought, expected out in mid-2013, and published two essays in Robert Mayhew's Essays on Ayn Rand's Atlas Shrugged: "Galt's Speech in Five Sentences (and Forty Questions)" and "A Note on Dagny's 'Final Choice'."

The first volume, Metaethics, Egoism, and Virtue: Studies in Ayn Rand's Normative Theory, was published in early 2011.