His works (especially his early works) tend toward relatively hard science, with minor expansions to scientific laws. Notably, his first book is entirely about scientific research. However, his later works tended to overshadow this with Filibuster Freefall - the original Trope Namer, "The Brain Eater", was a term used by James Nicoll to refer to the problems with later works by Hogan, among others.
His works include:
- The Giants Series:
- Inherit The Stars (1977)
- The Gentle Giants of Ganymede (1978)
- Giants' Star (1981)
- Entoverse (1991)
- Mission To Minerva (2005)
- The Two Faces Of Tomorrow (1979)
- Thrice Upon A Time (1980)
- Voyage From Yesteryear (1982)
- Code Of The Lifemaker (1983)
- The Immortality Option (1995) - sequel to Code of the Lifemaker
- The Proteus Operation (1985)
Manga comics based on some of his works were made:
- Hoshi O Tsugu Mono - adaptation of Inherit The Stars.
- Mirai kara no Hotline - adaptation of Thrice Upon a Time.
- Mirai no Futatsu no Kao - adaptation of The Two Faces of Tomorrow, translated back to English by Dark Horse Comics.
His works provides examples of:
- Author Tract: Hogan became infamous for writing these.
- Artistic License – History: In Code Of The Lifemaker, the Titanian alien civilization is supposed to resemble late medieval Italy, so it features a Catholic-like church, feuding city states, and a scientist ostracized for suggesting that the world is round...which never happened in real life. Europeans learned that the Earth was round during the time of Ancient Greece and that knowledge was never lost. The idea that belief in a flat Earth was widespread during the Middle Ages was invented during the 19th century, for the purpose of casting Christopher Columbus as a proto-Enlightenment thinker who achieved glory by challenging medieval superstition.
- Filibuster Freefall: His later works; as noted above, he was one of the original people described by the former Trope Namer, "The Brain Eater". In particular, his later works tended toward AIDS denialism, Velikovskyist catastrophism, and distrust of science.
- Let's See YOU Do Better!: How he got his start.
- Post-Scarcity Economy: In Voyage from Yesteryear, Earth's first interstellar colony, a planet orbiting Alpha Centauri, was settled by humans who were grown in automated incubators and raised and educated by robots. Huge automated factories produce all the basic material goods anyone could ever want, so the colonists have no use for, or even understanding of, the concepts of money or profit. Hogan asserts that there is very little crime on Chiron because most crime starts with wanting something that belongs to someone else and in this society the concept of ownership doesn't exist (but he then had both crimes and summary execution for them on Chiron feature prominently in the story).
- Superweapon Surprise: Voyage from Yesteryear focuses on Chiron, a human colony world orbiting Alpha Centauri, and the expedition sent from Earth to take control of the colony. The Chironians are uninterested in being taken over, so they fight back in subtle and nonviolent ways. They seem really confident of final victory despite the fact that the expedition has an army and a full array of heavy strategic and tactical weapons, and the Chironians don't. Then some of the Terrans notice that the old colony starship, the one that brought the original colonists to Chiron, has been fitted with a new experimental drive — an antimatter-based reaction drive, which produces a blast of high-energy radiation thousands of kilometers long...
- Time Travel: Hogan was fascinated by the whole idea of time travel and multiple timelines, and used it repeatedly in his fiction:
- Giants Series: at the end of Giants' Star, the escaping Jevlenese get caught in a malfunctioning wormhole and accidentally travel back in time as well as across space, to the Solar System of fifty thousand years ago.
- In The Proteus Operation, American scientists living in a Bad Future version of 1980 discover a way to travel back in time, and promptly do so. Their goal: change history by making sure Germany loses World War 2. They discover that in their timeline, Hitler was receiving support from another future timeline. Now they have to figure out what this other timeline is and accomplish their original mission, all without screwing up time still further.
- In Thrice Upon a Time, a Scottish scientist invents a machine that can send information through time - forward or back - and sets about figuring out just how the hell that's even possible. Along the way he and his friends and allies find themselves dealing with several Apocalypse How-level threats, one of which threatens all of human civilization while another could result in the destruction of the entire planet Earth.
