Question: is it possible to have:

`before_filter :authenticate_user! || :authenticate_admin!`

Answer: 
```
before_filter {authenticate_user! || authenticate_admin!}

```

Passing in a proc to the before\_filter method, would be the closest to what you have provided in you question.
Since `:authenticate_user!` is a symbol, `:foo == true` is valid. Therefore, your example will always just equate to `before_filter :authenticate_user!`

Try something like (not sure of your setup here..):

```
if method_defined?(:authenticate_user!)
  before_filter :authenticate_user!
else
  before_filter :authenticate_admin!
end

```

If you have both methods defined and want to run `authenticate_user!` then if that returns false, run `authenticate_admin!`, just make one `authenticate!` method that checks for uses/admin and run that `before_filter`.