There are some pretty bizarre things you can do with `method_missing` and public/private. But don't.

foo.rb

class Foo
  def call_private_bar
    bar
  end

private

  def bar
    :private_bar
  end

  def method_missing(name, *args)
    return :public_bar if name == :bar
    super
  end
end

foo = Foo.new
puts foo.bar # => :public_bar
puts foo.call_private_bar # => :private_bar

output

➜ ruby foo.rb
public_bar
private_bar