you mean sort of like in the version from before [your comment](https://github.com/mozilla-services/cornice/pull/130#discussion_r3377414)? :D

but sure, passing `schema=None` could easily cause confusion.  but instead of something like
```python
if 'schema' in args:
    schema = args['schema']
elif hasattr(ob, 'schema'):
    schema = ob.schema
else:
    schema = None
if schema is not None:
    validate_colander_schema(schema, request)
```
i'd rather go back to my original version, i.e. revert 04242358c5bed569c781da63687b34396954665a.  we'd end up with using `validate_colander_schema` in two places again, but it's more shorter and more readable that way, imho...