What is how to synthesize information from multiple sources?

How to synthesize information from multiple sources is a concept in personal epistemology: Combining information from multiple sources produces insights no single source contains.

Example: You have five separate notes in your Zettelkasten. One is about how startup founders often fail by optimizing for a single metric (from an article on Goodhart's Law). Another is about how ecosystems collapse when biodiversity drops below a threshold (from a documentary on coral reefs). A third captures the idea that resilient supply chains use multiple smaller suppliers rather than one dominant vendor (from a logistics case study). A fourth is about how jazz improvisation requires each musician to listen to every other instrument simultaneously (from a biography of Miles Davis). A fifth describes how the human immune system uses redundant pathways so that blocking one response does not disable the whole defense (from an immunology textbook). Each note, individually, is about its own domain. None of them mentions the others. But when you lay them side by side — physically or mentally — a pattern emerges that is not stated in any single source: systems that depend on a single channel of anything are structurally fragile, and the remedy is always distributed multiplicity. That pattern is not a summary of the five notes. It is a sixth idea — a new abstraction that only exists because you forced five unrelated observations into contact with each other. You write a new note capturing this principle, link it to all five source notes, and suddenly your Zettelkasten contains an insight that no author you read had articulated. That is synthesis.

This concept is part of Phase 43 (Information Processing) in the How to Think curriculum, which builds the epistemic infrastructure for information processing.