Take Parker Posey, who in “Irrational Man” plays Rita, an unhappily married professor who falls in love with Abe (Joaquin Phoenix), a brilliant but disillusioned philosophy professor. Allen expressed his pleasure over her performance. He explained that in working with actors that he delights in seeing them bring to life what are merely lines on a page, as with the “flair” that Posey brought to what he had written. He said that he rarely has to give instruction to his cast members.

“We never rehearse ,” he said. “They just come in and do it.”

The praise is mutual. Both Posey and Blackley, who portrays Roy, the jilted boyfriend of college student Jill, played by one of Allen’s favorites, Emma Stone, talked about how they appreciated working with Allen, who has cast Posey to be in his next film. “There is an enormous amount of talented actors who are around,” Allen said, “but not a lot of major roles.” He asserted that when you can offer actors good roles, even at scale, they will accept “because they like to act.” Allen has long been known as a director for whom actors would love to work, and he has succeeded to get many of the best for his films throughout his career.

Much of the talk at the conference consisted of questions regarding the issue of murder and morality that permeates “Irrational Man,” a title he settled upon after running through a host of alternative titles. One questioner, Robin Milling, asked if he ever had considered murdering anyone? This drew a big laugh.

“As a kid my obsessions were with magic, baseball and crime,” Allen said. He confessed that sometimes, when he lay awake in the middle of the night, he fantasized about committing the perfect crime, including methods of dispatching someone, like using cyanide, which figures in “Irrational Man.” But he made it clear that murder could not be morally condoned.

Most questions at the conference were directed at Allen, as one would expect. When asked how he felt about all the studies of his films that go on in classes and elsewhere, Allen was adamant in saying that he has no concerns with all of that. His enjoyment as a director comes from “the act of making a film,” he said, pointing to the pleasure and excitement he gets from involvement in everything that goes into the creation of a film. At 79, he intends to keep working, already having made 45 movies.

Allen noted that unexpected things happen with an audience when a film is shown. When Rita (Posey) says in “Irrational Man” that even if it were proven that Abe, the professor, had committed a murder, she would still go off to Spain with him, the line has gotten a laugh. That isn’t what Allen intended.

“Some laughs you mean to get when you do a comedy, some you get when you do a drama,” Allen observed, giving the impression that he would take them either way.