The two greatest exponents of applied psychology in the late 19th and early 20th Centuries were Sigmund Freud, the Austrian who founded psychoanalsis, and Carl Jung, the Swiss who pioneered analytical psychology. Despite being nineteen years apart in age, the duo were close friends for a short period of time.

In fact, the first time they met, according to the animated video (above), directed and animated by Andrew Khosravani for Aeon, Freud and Jung apparently conversed for thirteen hours.

Why, then, did such an intense relationship, which saw Freud all but anoint Jung as his true successor, fall apart? That is just the question that the video tries to answer. And no, it wasn’t just because Freud declared himself a father-figure of sorts to Jung and then proceeded to suspect that his “son” wanted to murder him.

One of the most famous feuds of science gets an entertaining – but no less useful for that reason – retelling in this video.