Capture excerpts, hypotheses, and connections with a single keystroke. Build a personal library of sources and notes you can draw on with perfect recall — so every claim in your work traces back to its source.
Download for MacYour reading doesn't wait. A footnote in tonight's paper, a stray claim in a seminar, a counterexample that arrives on a walk — anything can be the line a chapter turns on. Captured in a keystroke, sourced automatically, gathered into the references you cite when the argument arrives.
Mid-paper. Deep in the archive. In a seminar. Highlight what matters, hit the shortcut, and you're back to the page.
Leo automatically saves the context of your notes — article URLs, page numbers, podcast timestamps, video frames. So you can mark a passage in the middle of reading, and trace any line back to its source when you sit down to write.
Collect excerpts, hypotheses, and connections over months and across sources. The line you marked last semester is still there this one — sourced, searchable, ready to cite. Years of reading become the references you draw on when the chapter arrives.
Ask across everything you've read — what does the literature actually say, where do the sources disagree, what's the strongest counter-claim — and build the argument you'll defend when it counts. Use Leo's built-in model, or connect it to your favourite LLM.
Note the puzzles, the contradictions, the gaps where the literature still hasn't answered cleanly. Months of small notations sharpen into the question your work will answer.
Save the passages, findings, and quotations that sharpen your thinking. Build a personal library of evidence — every line traced to its source — to draw on as your argument takes shape.
Track the scholars whose work surrounds yours. Capture what's been claimed, where the disagreements sit, where the gaps remain. Papers, citations, conference talks, working drafts — captured at the source.
Jot down a working theory the moment a source provokes one. Build a record of your evolving thinking — anchored to the material that shaped it, ready to revisit when the next piece of evidence comes in.
Capture the threads between sources the moment you spot them — Smith's footnote next to Chen's counterexample next to a line from this morning's seminar. Build the web of links that turns a pile of reading into an argument with a spine.
Argue the case on the page. Build a running record of the claims, the evidence, and the counter-evidence that survive scrutiny — so when you sit down to write the chapter, the argument is already earned, every line back to its source.
Galileo's notebooks tracked his telescopic observations night by night — the moons of Jupiter circling their planet, drawn at intervals as the geometry resolved. The sketches survive in his hand at the Biblioteca Nazionale. Sidereus Nuncius, the seventy-page pamphlet that overturned Aristotelian cosmology, came straight out of those pages.
Humboldt spent five years in the Americas with notebooks strapped to his pack — temperatures, plant distributions, indigenous languages, the shape of every mountain he climbed. He filled volume after volume in the field. Cosmos, his attempt to describe the natural world as one connected system, was three decades of unpacking those notebooks back in Berlin.
A year after the Beagle returned, Darwin opened a small leather notebook and labeled it B. By page 36 he had drawn the first tree of life and written "I think." above it. On the Origin of Species came twenty-two years later — most of them spent expanding the case Notebook B already contained in seed.
Curie's laboratory notebooks from the 1890s — the years she and Pierre isolated radium and polonium — are still radioactive. They are read at the Bibliothèque Nationale through lead-lined boxes. Two Nobel Prizes, two new elements, and the founding of radiation chemistry trace back to those pages.
Mead arrived in Samoa at twenty-three with a typewriter, a stack of notebooks, and instructions from Franz Boas to describe adolescent life. She filled the notebooks with kinship charts, conversations, daily routines, and her own evolving questions. Coming of Age in Samoa came out three years later — drawn directly from those pages, and read across a generation of cultural anthropology.
For thirteen years Benjamin filled notebooks with quotations, advertisements, photographs, and observations from nineteenth-century Paris — reading the city as a text. He organized them into thirty-six folders he called the Konvolute. The unfinished Arcades Project, published in fragments after his death, is the notebook itself, more or less, as the book.
As a young physicist, Feynman kept a notebook he titled Notebook of Things I Don't Know About, reorganizing physics from the bottom up so he could see what he understood and what he didn't. He worked through the fundamentals in his own hand, deriving from first principles. The Lectures on Physics — three volumes that taught a generation — were the same exercise, performed at the blackboard.
