In 1836 he graduated from the Sorbonne under Joseph Victor Leclerc with a thesis on Aristotle's Physics (published in 1854 as his book De quelques points des sciences dans l'antiquité) and Sur l'étude et l'enseignement de la grammaire (Paris 1836).
Jullien was most notable as an author of grammatical and literary textbooks for schools for the publisher Louis Hachette.
As associates of that publishing house he and Édouard Sommer also helped Émile Littré create his dictionary.
Nostalgic for the First French Empire and an anti-Romantic thinker, he preferred 18th century Age of Enlightenment rationalism and so could not gain a foothold on the university career ladder before the rise of the French Second Empire - as seen in the preface to his 1844 Histoire, he felt himself unfairly treated.
His thinking and wide reading fully developed under Napoleon III in six extensive theses on grammar, literature, history, and philosophy and was more devoted to clarity than originality.