Here's why:

* Cells are the fundamental units of life: The cell is the smallest unit that can carry out all the processes necessary for life, such as metabolism, growth, and reproduction.

* All living things are made of cells: Whether it's a single-celled bacterium or a complex human being, all living organisms are composed of cells.

* Viruses are not considered living: While viruses can reproduce and evolve, they lack the fundamental characteristics of life, such as the ability to carry out metabolism independently. They require a host cell to replicate.

Therefore, the existence of a living organism without cells is not scientifically supported.