We can then ask whether a rule of the "syntax" could refer to or alter word-internal morphological structure. This possibility ought to be excluded insofar as the Lexicalist Hypothesis is correct, since the essence of this (at least in a relatively strong variant which has genuine empirical content, which we have assumed in this work) is precisely the claim that the syntax neither manipulates nor has access to the internal form of words.
- Anderson (2004b), Pag. 295