Magic = Leadership (at least by Celestia, near the end of Magical Mystery Cure)
"From one to another, another to one. A mark of one's destiny singled out alone, fulfilled"
"From Day to Night, Night to Day. One single Sister, out alone, Rule"
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Magic is just advanced Science.
Faith is just unreasonable Trust.
Trust is the only thing necessary for plain simple Leadership.
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Then, Twilight is the one bringing together the "sense of communal unity" from common values (superstition), with the "necessity of meaning" (reason) from the scientific method [in other words: Friendship & Destiny ]
"From all of us together, together we're friends. With the marks of our destinies made one, there is magic without end!"
"Helping each others, together as friends. Each of their destinies they forge, into one. In Friendship , Forever."