Category Theory for the Sciences (The MIT Press)

I find Category Theory very difficult. This book looks like it's more accessible than the others I've tried.

I decided that I needed a formal category theory background when trying to understand typeclasses in Haskell. This book perfectly serves the aim, introducing the theory in a formal yet not too abstract way. The application to databases and ologs is nice. The book has a formal structure of a mathematical text (definitions, propositions, theorems, however often without a proof) and a lot of examples. Has a minor drawback though, namely a relatively high density of typos, but I guess it's a common first edition symptom.

This is a great and accessible book on applied category theory that is accessible to people who are not experienced mathematicians.

This book is useful for SIMULINK and MySQL modeling.

A very accessible and informative book on broad applications of category theory. Especially useful in information technology modelling

David Spivak is a welcome new breed of MIT lecturer whose passion is to motivate, engage, and facilitate a students learning of a subject. Its predecessors are "Category Theory for Computer Scientists" Barr & Wells, "A First Introduction to Categories" - Lawvere & Schnauel, and "Category Theory" -Awodey. This book is a Rosetta Stone for understanding the forthcoming new applications of Category Theory to real world issues such as the foundations of computer science (e.g., Algebraic Theory of Machines - Jack Rhodes and Ken Khon) and physics ( e.g., John Baez). Where was Spivak when one first encountered the new and ethereal Category Theory in the late 1950's under Dan Kan, Warren Ambrose, and Serge Lang. Closest comparison would be BUD/S training. And let us not forget the esteemed George Whitehead classes ( e.g. "Elements of Homotopy Theory" which was based on his lectures ): --- Enter the class room; start writing as fast as possible on the blackboard mimicking tap-dancing squirrels, and when reaching the end of the blackboards erasing the first board. Carpal Tunnel Syndrome for the few survives of his course. As with Barr & Wells, Spivak supplies answers that facilitate grasping the underlying metaphors of the subject presented with instant feedback allowing a natural progression of the subject. He smoothly inculcates the reader with the metaphors for further study such as Grothendieck Construction and Topos theory. Peter T. Johnstone's Olympian "Topos Theory " (Dover) and "Sketches of an Elephant" are the ultimate in joyous reading for the mathematically 'deranged' who cannot get enough. Only one kvetch. The printing of the text is so light that one wonders if MIT Press had run out of toner, making reading a chore for older readers.In contrast, Norbert Wiener's "Cybernetics 2", 1960 is still readable because real ink was used. In conclusion Spivak's book is a joy and an important gateway for a scientist of the new emerging fields.