Since the introduction of terms like "cyberspace" and "virtual reality", the term "Virtual" has been attached to a range of projects including using computers to draw buildings, distributed studio projects and heavily technologically dependent interfaces for "sensing" digitally modeled environments. The only common aspect of these "virtual" projects is their use of computers. As a way to re-infuse meaning to the term Virtual, the paper describes a theoretical basis for understanding the meaning of being virtual (as opposed to being "Real, Actual" or "Possible") with special attention to the manipulation of ideas as is the case in designing architecture.