[2][3] He concludes that paranormal events are rare, unpredictable and capricious and need a paradoxical combination of skillful scientific experiment with a childlike excitement to be seen and recorded.

In The Psychology of the Psychic Marks coined the term "Koestler's Fallacy" as the assumption that odd matches of random events cannot arise by chance.

[1] In "Psychology and the Paranormal: Exploring Anomalous Experience" Marks (2020) modifies his position by suggesting that a few coincidences are so extremely improbable that they warrant more serious scientific attention.

John Beloff gave the book a mixed review, describing it as "a typical Koestlerian performance" but noting that some of his claims about psychical research were inaccurate.

[citation needed] "The Roots of Coincidence" is also the name of an instrumental by fusion jazz ensemble Pat Metheny Group, featured on their 1997 album Imaginary Day.