Fodor and Pylyshyn on Connectionism


Levels of description

The (in)famous argument

  1. Connectionism is either a theory at the implementation level, or it is a theory at the level of representation and algorithm.
  2. If it is the former, then it is compatible with LOT.
  3. If it is the latter, then it is also compatible with LOT.
  4. So connectionism is compatible with LOT.

Argument for P2

  • LOT can be implemented by neural networks or in other ways.

Argument for P3

  • Connectionism must be compatible with LOT at this level in order to explain systematicity, productivity, inferential coherence.
    • Systematicity - if you can think A loves B, you can also think B loves A.
    • Productivity - you can have an indefinite number of different thoughts
    • Inferential coherence - being able to carry out coherent reasoning, e.g. if every cat can meow, and Garfield is cat, then Garfield can meow.


  • Any counterexample to systematicity?