In literary theory and aesthetics, authorial intent refers to an author's intent as it is encoded in their work. Authorial intentionalism is the hermeneutical view that an author's intentions should constrain the ways in which a text is properly interpreted. Opponents, who dispute its hermeneutical importance, have labelled this position the intentional fallacy and count it among the informal fallacies.

There are in fact two types of Intentionalism: Actual Intentionalism and Hypothetical Intentionalism. Actual Intentionalism is the standard intentionalist view that the meaning of a work is dependent on authorial intent. Hypothetical Intentionalism is a more recent view; it views the meaning of a work as being what an ideal reader would hypothesize the writer's intent to have been — for hypothetical intentionalism, it is ultimately the hypothesis of the reader, not the truth, that matters.

Extreme intentionalism, the classic and most substantial form of intentionalism, holds that the meaning of a text is determined solely by the author's intent when he creates that work. As C.S. Lewis wrote in his book An Experiment in Criticism, "The first demand any work of art makes upon us is surrender. Look. Listen. Receive. Get yourself out of the way." Lewis directed readers to sit at the feet of the author and submit to the author's authority to understand a work's meaning — to comprehend a work, a reader must understand what it is that the author is trying to communicate to his audience. This position acknowledges that such can only apply when what the author intends to convey can actually be conveyed by the language that he uses. If an author uses words that cannot, by any reasonable interpretation, possibly mean what he intends, then the work is simply random noise and meaningless nonsense.

A prominent proponent of this view is E.D. Hirsch, who in his influential book Validity in Interpretation (1967) argues for "the sensible belief that a text means what its author meant". Hirsch contends that the meaning of a text is an ideal entity that exists in the author's mind, and the task of interpretation is to reconstruct and represent that intended meaning as accurately as possible. Hirsch proposes utilizing sources like the author's other writings, biographical information, and the historical/cultural context to discern the author's intentions. Hirsch notes a fundamental distinction between the meaning of a text, which does not change over time, and the significance of the text, which does change over time.

Extreme intentionalism holds that authorial intention is the only way to determine the true meaning even in the face of claims that "the author often does not know what he means". Hirsch answers said objection by distinguishing authorial intent from subject matter. Hirsch argues that when a reader claims to understand an author's meaning better than the author himself, what is really happening is that a reader understands the subject matter better than the author; so the reader might more articulately explain the author's meaning — but what the author intended is still the meaning of the text he wrote. Hirsch further addresses the related claim that authors may have unconscious meanings come out in their creative processes by using various arguments to assert that such subconscious processes are still part of the author, and so part of the author's intent and meaning, for "How can an author mean something he did not mean?"

Kathleen Stock's book Only Imagine: Fiction, Interpretation, and Imagination (2017) takes an extreme intentionalist stance specific to fictional works. She argues that for fictional content to exist in a text, the author must have intended the reader to imagine that content. The reader recognizes this authorial intention and uses it as a constraint on what is properly imagined from the text.

Weak intentionalism (also called moderate intentionalism) takes a more moderate stance and incorporates some insights from reader-response; it acknowledges the importance of authorial intent while also allowing for meanings derived from readers' interpretations. As articulated by Mark Bevir in The Logic of the History of Ideas (1999), weak intentionalists see meanings as necessarily intentional, but the relevant intentions can come from either authors or readers.

Bevir argues that texts do not contain intrinsic meanings separable from the minds interpreting them. Meaning arises from the intentions of the person engaging with the text — whether that is the author producing it or a reader consuming it. However, Bevir privileges the author's intentions as the starting point for interpretation, which then opens up a space for negotiating meanings with readers' perspectives.