Astrophysicist Neil deGrasse Tyson returns for this episode of Rationally Speaking, with a particular question to discuss: Should he call himself an atheist? The impetus is a recent dust-up over Neil's appearance on Big Think, in which he explained that he avoids the label "atheist" because it causes people to make all sorts of unflattering (and often untrue) assumptions. Julia and Massimo reply with some counterarguments, and along the way delve into the philosophy of language.

This episode features special guest Zach Weinersmith, author of "Saturday Morning Breakfast Cereal," a popular webcomic about philosophy and science. Zach clarifies his position in the ongoing "philosophy vs. science" fight, poses a question to Julia and Massimo about the ethics of offensive jokes, and discusses BAHFest, his "Bad Ad Hoc Hypotheses" conference lampooning evolutionary psychology and his movie "Starpocalype." Somehow along the way, the three take a detour into discussing an unusual sexual act.

Those among us who loathed high school calculus might feel some trepidation at the premise in this week's episode of Rationally Speaking. MIT Physicist Max Tegmark joins us to talk about his book "Our Mathematical Universe: My Quest for the Ultimate Nature of Reality" in which explains the controversial argument that everything around us is made of math. Max, Massimo and Julia explore the arguments for such a theory, how it could be tested, and what it even means.

On this episode, recorded live at the Jefferson Market Library in New York City, Rationally Speaking podcast celebrates its 100th episode! The show features a full hour of audience Q's and Julia & Massimo's A's. Topics range from science, philosophy and the borderlands between the two. The questions push the hosts to think on their feet, and even to admit their ignorance on stage!

Creative geniuses are always a little bit cuckoo, right? At least, that's the impression you'd get from TV, movies, and plenty of common wisdom. In this episode of Rationally Speaking, Massimo and Julia are joined by psychologist Judith Schlesinger, author of The Insanity Hoax: Exposing the Myth of the Mad Genius, who explains why she thinks the "mad genius" archetype is simply the result of folklore, misunderstanding, and bad research.

What qualifies someone as mentally ill? The standard for diagnosis is the Diagnostic and Statistical Manual of Mental Disorders (DSM), which just released a 5th edition in 2013 -- but just how objective is it? This episode of Rationally Speaking features Dr. Jerome Wakefield, psychiatrist, PhD in philosophy, and author of "The Loss of Sadness: How Psychiatry Transformed Normal Sorrow into Depressive Disorder." Julia, Massimo and Jerome talk about the arbitrariness of the DSM and the controversies around the boundaries of various mental disorders, including depression and sexual fetishes.

Few philosophers have as wide of an impact on the general public as ethicist Peter Singer, this week's guest on Rationally Speaking podcast. Singer's utilitarian arguments about how we should treat animals, why we have a moral obligation to give to charity, whether infants should count as "people," and more have won him widespread fame -- and notoriety -- over the last few decades, and launched multiple movements. Tune in to hear his discussion with Massimo and Julia about why he's a utilitarian, and how his views of utilitarianism have recently changed (and find out how he influenced Massimo's life years ago).

It seems like a week can't go by without a news story about how neuroscience has discovered the neurological basis of love, morality, addiction, you name it. Yet how much explanatory power does neuroscience really have -- and are we putting too much trust in its findings? On this episode of Rationally Speaking, Massimo and Julia explore these questions with psychiatrist Sally Satel and professor of psychology Scott O. Lilienfeld, the authors of "Brainwashed: The Seductive Appeal of Mindless Neuroscience."

Is the mind a kind of computer? This episode of Rationally Speaking features philosopher Gerard O'Brien from the University of Adelaide, who specializes in the philosophy of mind. Gerard, Julia, and Massimo discuss the computational theory of mind and what it implies about consciousness, intelligence, and the possibility of uploading people onto computers.

What's the difference between science and pseudocience -- and is it even possible to draw a clean line separating them? In this episode of Rationally Speaking, Massimo and Julia interview philosopher Maarten Boudry from Ghent University. Tune in to hear them discuss Massimo and Maarten's new book, "Philosophy of Pseudoscience: Reconsidering the Demarcation Problem"... and stick around to learn how Maarten pranked theologians.