Scott's problem with Lacan: The theory focuses too much on the individual subject. It also tends to universalize categories without contextualizing them, thus, "the outcome for historians is a reductive reading of evidence from the past…it does not permit the introduction of a notion of historical specificity and variability" (39).
Historians using these two variants of psychoanalytic theory run into problems as well. They seem to accept fixed relations between male/female as being universal (and consequently ahistorical). And this has problems because it leads us to an "essentialist notion of woman" (40). NB: look up essentialist in a good dictionary