Benjamin Betts was a 19th Century psychologist from New Zealand, and these intricate diagrams are taken from Geometrical psychology, or, The science of representation: an abstract of the theories and diagrams of B. W. Betts (1887) by Louisa S. Cook. Through this series of geometric forms, he was attempting to visualise the mathematics of human consciousness.

The imagery he generates takes on a delicate, organic structure resembling flowers and crystals. Taken from the introduction:

…. The fact that he has accidentally portrayed plant-forms when he was studying human evolution is an assurance to Mr. Betts of the fitness of the symbols he has developed, as it affords presumptive evidence that the laws he is studying intuitively admit of universal application.

 

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Images taken from an original post by the Public Domain Review, found here.