Core Concepts

Cortex is built on well-established principles from cognitive science and knowledge management. Understanding these concepts will help you get the most out of the system.

The Four Pillars

1. Zettelkasten Notes

The Zettelkasten method is a note-taking system invented by sociologist Niklas Luhmann. The core principle: one atomic idea per note, connected to other notes through meaningful links. Cortex enforces this structure to keep your knowledge clean and navigable.

2. Semantic Recall

Semantic recall lets you query your knowledge graph in natural language. Instead of searching for exact keywords, you describe what you’re looking for — and Cortex finds the relevant notes using embedding similarity, full-text search, and graph traversal.

3. Spaced Repetition

Spaced repetition is a learning technique that shows you information at increasing intervals, right before you’re about to forget it. Cortex auto-generates flashcards from your notes and schedules reviews using an adaptive algorithm.

4. Knowledge Graph

Your knowledge graph is the web of connections between your notes. Every link, every tag, every semantic similarity creates structure. Over time, this graph becomes a map of how you think.

How They Work Together

Create Note → Auto-Link → Knowledge Graph grows
                ↓
         Generate Flashcard → Spaced Repetition
                ↓
         Semantic Embedding → Recall queries work better
                ↓
         Activity Stream → You see your brain working

Each note you create strengthens every other part of the system. More notes mean better recall. Better recall means more useful insights. More insights mean deeper notes.