Hence, like self, it is, in the strictest sense, a substantival pronoun.
"The English Language"
Robert Gordon Latham
Archbishop Whately has some remarks on this substantival power in his Logic.
"The English Language"
Robert Gordon Latham
The prepositions of deflection, when complex, originate chiefly in nouns, accompanied by an absolute preposition; as instead of of substantival, between of adjectival origin.
"The English Language"
Robert Gordon Latham