don't have their own existence vs don't have existence

Examples:

• The characters in the story don't have their own existence; they only exist within the narrative created by the author.
• These ideas don't have their own existence; they are borrowed from various philosophical schools.
• In a virtual world, avatars don't have their own existence; they are controlled by the players.
• The shadows on the wall don't have their own existence; they are just projections of objects in front of the light source.
• The memories we hold don't have their own existence; they are constructed and reconstructed by our minds.

Alternatives:

• don't exist independently
• lack individual existence
• are not self-existent
• are dependent on something else for existence
• are not self-sustaining

Examples:

• Unicorns don't have existence in the real world; they are mythical creatures.
• In the realm of science fiction, time travel doesn't have existence as we understand it.
• The concept of a perpetual motion machine doesn't have existence in the laws of physics.
• In his mind, the idea of failure doesn't have existence; he only focuses on success.
• For some people, the supernatural doesn't have existence; they believe only in the natural world.

Alternatives:

• do not exist
• are non-existent
• have no existence
• lack existence
• are devoid of existence