and to attempt to answer them one must drift into the realms of unsubstantiated inventions and wild conjecture…
From this point forth, we shall be leaving the firm foundation of fact and journeying together through the murky marshes of memory into thickets of wildest guesswork. — Albus Dumbledore.
[Further points to ponder – Is Magic a psychological, physical or spiritual power. Logic would dictate a blend of all three, or perhaps some sort of bonding power between those elements (bear in mind the need for one to visualise, understand a spell and preform the correct physical movements to elicit a physical or other reaction). Understanding this is the key to understanding many of these questions, particularly those involving magical theory and perception]
For a fascinating read and a great enjoyable book, which is revolving around the very issue you bring up here, read Harry Potter and the Method of Rationality, by Eliezer Yudkowsky (Jewish? No hint of it). Available free online [no links allowed, just google it!]
I believe I have recommended this to you in the past, in person.