around method with no primary

[Bruce Lester <72110.1107@CompuServe.COM>]

I got an error message that I was unable to get rid of without creating a dummy
primary method.

I have a generic function with an around method that is applicable to all
possible parameters.  I use the around method to check the parameters for
validity before calling CALL-NEXT-METHOD and the CLOS framework.  

Why do I have to have a primary method for a set of parameters that the around
method handles?

Thanks.