If those tasks are intended to define nursing

You're not really reading what I'm saying. Those tasks, are just one aspect of nursing. And important ones. The idea that a secretary or a social worker regularly carry out nursing tasks makes me laugh by the way

Feeding the patient to managed caloric needs, washing to minimize infection, toileting to prevent skin breakdown all of these are interventions that can and are generally ordered by a provider

I have never once seen a doctor order washing and feeding a patient. Or toileting. You yourself just gave good example of an answer to your question. An example of a scientific principles that nurses need to know.

So yeah those tasks are one aspect. As a nurse I have training in pharmacology, pathophysiology, psychology, it's not as in depth as a specialist, but it's still there. They're vital in safely administering medications, recognising the deteriorating patient, interpreting vital signs, dealing with confused and aggressive patients.

I think maybe I'm misunderstanding the point of your post. You say you want to know what Nursing is, but i feel like you just want to debate what you already suspect, that nursing doesn't qualify as a profession, based on your view of empirical evidence as the be all and end all. Well good luck to you. I maintain that nursing is the providing of a range care, prescribed by a doctor, administered by professionals