Your question was: "If two entities cannot interbreed, are they different species?"
I was only allowing that there can be other reasons that two entities (of the same species) could be unable to interbreed. Sorry didn't intend getting involved in semantics, just being cautious.
People are different from chimps and all other animals because we have a soul. I don't even want to think about what kind of experiments are going on to breed humans and animals. Ewwww!
So what is your test to separate chimps from dogs? You still haven't given a definition of kind. Postulating a "soul" is no better unless you can distinguish entities with a soul from those without.
The definition of species is and always has been full of arbitrary definitions. The only thing necessary to define a species is whether, in fact, groups interbreed. Not whether forced matings produce offspring, but whether unforced mating occurs.
Populations can be separated by geography or by something as simple as a variation of some signal, like a mating dance, a call, or a pheromone. The change might be trivial, but result in two, non-interbreeding populations, capable of additional differentiation.