Sic et non
from 1120 Abelard's compilation, around 1120
Set the authorities that say yes beside the authorities that say no, with equal weight and no resolution, and let the contradiction do the teaching.
- Active
- from 1120
- Where
- Paris
- Also
- sic et non
- Status
- In use
- Tradition
- Classical procedures
What it is
Abelard collected 158 questions and, under each, the passages from scripture and the Fathers that answered yes alongside those that answered no. He supplied no resolutions. The contradictions were left standing.
The method is the arrangement itself. Placing the conflicting texts side by side, with nothing to soften the collision, forces the reader to do the reconciling and makes it impossible to pretend the tradition speaks with one voice.
How it works
State the question. Assemble the authorities on one side, quoted fully. Assemble the authorities on the other, quoted equally fully. Give neither more space nor more emphasis. Stop.
Abelard's prologue supplies the tools for resolution — check the text, check the context, check whether the author changed his mind, check whether the words are used in the same sense — but he applies them to none of the 158 questions.
The moves, in order
- Pose the question
- Assemble the authorities affirming it, quoted at length
- Assemble the authorities denying it, quoted at equal length
- Give neither side emphasis or precedence
- Leave the contradiction standing as the finding
The procedure
Proposition The two engineering reports on this slope cannot both be right.
- The question is whether the slope requires stabilisation before building.
- On the yes side: the 2023 geotechnical report finds a shear plane at four metres and recommends piling; the council's own hazard mapping places the lot in a landslip risk zone; two adjacent lots were required to pile.
- On the no side: the 2025 report by a differently qualified firm finds the same shear plane but assesses it as relict and inactive; the district's post-2000 slip register records no movement on this aspect; the mapping is acknowledged in its own notes to be indicative only.
- Both sets are set out in full, with the same detail, and neither is characterised as the better opinion.
Therefore The contradiction is exhibited rather than resolved, and what it establishes is that the question turns on whether the shear plane is active — which neither report addresses directly and which is what must now be determined.
The value of refusing to resolve is that it locates the real disagreement. A summary that picked a winner would have buried the one question that actually decides the matter.
What it is good for
Exposing the point at which experts actually diverge, which is usually much narrower than their conclusions suggest. It is also the honest way to present a literature that does not agree.
Where it fails
It stops before the useful part. Exhibiting a contradiction is genuinely valuable and it does not tell anyone what to do, and someone eventually has to decide. Abelard was rightly criticised for producing an instrument and declining to use it.
It is also open to abuse by selection. Equal space for both sides is a real virtue when the sides are genuinely balanced and a serious distortion when they are not — the modern version is the false-balance problem in reporting.
Common misconceptions
That Abelard was attacking the authorities. He was not; he was demonstrating that they need interpretation, which is a claim about the reader's obligations rather than the texts' authority. The Church of his day was not persuaded of the distinction.
Where it came from
Abelard's Sic et Non, compiled around 1120, with a prologue setting out rules for reconciling apparent contradictions that the body of the work conspicuously does not apply.
What became of it
Its structure was absorbed into the disputatio, which added the resolution Abelard withheld. The method's own descendants are the literature review and the balanced brief.
Lasting influence
It made the scholastic method possible by establishing that contradiction within the tradition was a problem to be worked on rather than a scandal to be denied.
Why it still matters
Alive wherever conflicting expert evidence has to be presented fairly.
Put another way
Two witnesses in the same room, neither interrupted.
Texts
Peter Abelard, Sic et Non
The prologue is the philosophically interesting part; the 158 questions are the demonstration.
Where to start
Read the prologue. It is a short and remarkably modern piece of textual criticism.
The surprising bit
The book that made medieval theology possible was written by a man the Church twice condemned, and it works by declining to say anything at all.
In their own words
By doubting we come to inquiry, and by inquiry we perceive the truth
Who held it
the Fathers
Connections
- Influenced
- The disputatio, The principle of charity
- Parallel to
- Aporia
The verdict
An honest instrument that deliberately stops one step short of being useful, and is valuable precisely for stopping there.