It’s analytical in the philosophical sense of being true by virtue of the meanings of the words, in this case ‘reason’. It’s also a tautology, via sentential logic:
A ------> A
A
A
Here’s the truth table: A : A ---------> A
____________T__T T T
____________F__F T F
Since the column under the conditional connective (---------->) is made up of all T’s, we have a tautological sentence in sentential logic. It is always true. There’s your proof.
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