The phrase "a real existence" is correct and usable in written English.
It can be used when discussing the concept of something having an actual, tangible presence or being in reality, as opposed to being imaginary or theoretical.
Example: "The debate about whether virtual worlds can have a real existence continues to spark interest among philosophers and technologists."
Alternatives: "an actual existence" or "a tangible existence".
As the creationist natural philosopher Whewell (the man who coined the term "science") put it, "Species have a real existence in nature and a transition from one to another does not exist" (Whewell 1837; Hull 1973; [in a later edition "transition" is changed to "transmutation"; Whewell 1858]).
The Athenian philosopher Plato believed that mathematical entities are not just human inventions but have a real existence.
"It is the fact that our existence is not a real existence, it's a precarious existence; it's always undermined by the thought of death, by time, by decay".
Later, looking at a wild flower on the beach, she realized that objects have a real existence beyond our illusions about them.
But it's worth remembering that Zehaf-Bibeau talked not just about an external battle but an internal struggle with demons, spiritual beings he felt had a real existence.
Moreover, according to some interpretations, the new theories demolished the basic metaphysical assumption of earlier science that the entire physical world has a real existence and objective properties independent of human observation.
For instance, real existence (i.e., the existence of a real being) is a temporal determination, whilst ideal existence is compossibility.
It is doubtful whether it ever had any real existence.
There are states that purport to control what happens within their borders but hardly have any real existence.
Others have deleted them to live a more "real" existence.
The final stage of a Davisian cycle was called a peneplain, the real existence of which, or otherwise, became controversial.
