Rails - Oct 2005 - disable cache/action caching but keep fragments ?

Hi.

For an auth generator I work on, I want to be able, for obvious
reasons, to disable cache/action caching even the developer used them
but still keep fragment caching as it doesn''t have any security
impact.

Is there a way to do that ? I tried :

ActionController::Base.define_method(:caches_page) { }

as explained on IRC, but I get :

   1613 NoMethodError (private method `define_method'' called for
ActionController::Base:Class).

Any hints ?