“You are a mashup of what you let into your life,” artist Austin Kleon observed. Since creativity is combinatorial, the architecture of mind and character is deeply influenced by the intellectual stimulation we choose to engage with — including the books we read. There is hardly anything more fascinating than the private intellectual diet of genius — like this recently uncovered list of books computing pioneer and early codehacker Alan Turing (June 23, 1912–June 7, 1954) borrowed from his school library. Though heavy on the sciences, the selection features some wonderful wildcards that bespeak the cross-disciplinary curiosity fundamental to true innovation. A few personal favorites follow.

1. SIDELIGHTS ON RELATIVITY (1922)

Sidelights on Relativity, published in 1922, is a two-part book based on a series of lectures Albert Einstein gave between 1920 and 1922. It begins with “Ether and the Theory of Relativity,” explores the nature of ether and the idea that the universe is not mechanical through the lens of Newton, Maxwell, and Lorentz’s work, and the implicit contraction of “space without ether.” The second part, “Geometry and Experience,” considers the concept of infinity through Euclidean geometry.

The book is available as a free download from Project Gutenberg.

2. THROUGH THE LOOKING GLASS (1871)

The follow-up to Lewis Carroll‘s Alice’s Adventures in Wonderland (also on Turing’s reading list), Through The Looking-Glass, and What Alice Found There — one of the best classic children’s books with timeless philosophy for grown-ups — has a palpable philosophical undercurrent running beneath the seemingly nonsensical dialogue and situations, inviting the reader to extract his or her own conclusive existentialism.

Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!” ~ The Queen

A study in contrasts and opposites, the book is as much escapism from reality as it is a journey into our most authentic, uninhibited selves.

Also in the public domain, the book was the 12th text to be digitized by Project Gutenberg.

3. SCIENCE AND THE MODERN WORLD (1925)

Science and the Modern World by Alfred North Whitehead, originally published in 1925, is one of the seminal texts of modern science, presaging nearly a century of cutting-edge discoveries by examining science in the richer context of culture and the humanities as a force of social progress — a conceptual predecessor to what Jonah Lehrer has termed “the fourth culture”.

Philosophy, in one of its functions, is the critic of cosmologies. It is its function to harmonise, re-fashion, and justify divergent intuitions as to the nature of things. It has to insist on the scrutiny of the ultimate ideas, and on the retention of the whole of the evidence in shaping our cosmological scheme. Its business is to render explicit, and—so far as may be—efficient, a process which otherwise is unconsciously performed without rational tests.”

The Internet Archive has a free download.

4. THE UNIVERSE AROUND US (1929)

English astrophysicist Sir James Jeans was an early champion of “popular science.” In The Universe Around Us, he set out to make cosmogony, evolution, and the general structure of the universe “intelligible to readers with no special scientific knowledge” by rewriting and reforming lectures and “wireless talks” he had given to academic audiences.

In the second edition of the book, Jeans added a discussion of “the new planet Pluto,” whose planetary status has since been revoked, as well as the rotation of the Milky Way and “the apparent expansion of the universe.” By the fourth edition in 1943, Jeans had distilled the discovery of atomic nuclei, suggesting it could “not only give a satisfactory account of the radiation of the sun and stars, but can also explain many hitherto puzzling stellar characteristics.” In a way, the changes across the four editions offer a fascinating footprint of some of the most important discoveries in modern science, narrated in near-real-time by a scientist who made it his life’s work to foster a popular understanding of the scientific method.

5. MATTER AND MOTION (1876)

In 1876, pioneering physicist James Clerk Maxwell, best-known for formulating electromagnetic theory, penned Matter and Motion — the first comprehensive guide to the fundamental principles of elementary physics, pulling the curtain on the logic and rationale of the concepts his work built upon, presented in order of complexity in an effort to build a layered understanding of the timeless laws of physics.

Physical science, which up to the end of the eighteenth century had been fully occupied in forming a conception of natural phenomena as the result of forces acting between one body and another, has now fairly entered on the next stage of progress – that in which the energy of a material system is conceived as determined by the configuration and motion of that system, and in which the ideas of configuration, motion, and force are generalised to the utmost extent warranted by their physical definitions. To become acquainted with these fundamental ideas, to examine them under all their aspects, and habitually to guide the current of thought along the channels of strict dynamical reasoning, must be the foundation of the training of the student of Physical Science.

The book is available for free in multiple formats, courtesy of The Internet Archive.

Alex Bellos has the full list. Many of the books are now in the public domain and are thus free.

Complement with the reading lists of Oliver Sacks, Carl Sagan, David Byrne, Joan Didion, Leo Tolstoy, Susan Sontag, Alan Turing, Brian Eno, David Bowie, Stewart Brand, and Neil deGrasse Tyson.