Synthesis is the integration of multiple sources, ideas, or pieces of evidence into a unified argument. Where analysis works on a single piece of evidence, synthesis works across several, showing how they relate to each other and to the essay’s thesis.
Synthesis is not summary. Summarizing three sources in sequence (“Smith says X. Jones says Y. Lee says Z.”) is a list, not a synthesis. Synthesis puts the sources in conversation: “Smith and Jones agree that X, but they disagree about its cause — Smith attributes it to A, while Jones argues for B. Lee’s data complicates both positions by showing C.”
The synthesizing move has three forms:
- Agreement synthesis — multiple sources support the same point from different angles. The writer shows how converging evidence strengthens the claim.
- Disagreement synthesis — sources contradict each other. The writer maps the disagreement, evaluates the competing positions, and either takes a side or shows what the disagreement reveals.
- Complication synthesis — a new source doesn’t support or contradict but complicates the existing picture. The writer shows how the complication enriches understanding rather than resolving it.
Synthesis is where the essay writer’s thinking is most visible. Anyone can report what individual sources say; synthesis requires the writer to see relationships between sources that the sources themselves may not articulate. This is why synthesis is the skill that most distinguishes college-level writing from high school writing and professional scholarship from undergraduate work.