From time to time I observe ‘as an historian’. For some, it sounds right, for others who know the rule ‘an’ before words that begin with a vowel and ‘a’ before words that begin with a consonant, it seems misplaced because historian begins with a consonant. This brings us to one of the things I love about the English language, its nuance.
Yes, ‘h’ is a consonant, but in words like ‘habitual’, ‘heredity’, ‘historian’, ‘historical’, ‘hysterical’, it is less pronounced — or aspirated to use the technical term — than in words such as ‘hateful’, ‘hear’, ‘holiday’, ‘how’, ‘hurt’. As the grammarian’s grammarian, the esteemed Henry Fowler, noted:
… an was formerly used before an unaccented syllable beginning with h and is still often seen and heard (an historian, an hotel, an hysterical scene, an hereditary title, an habitual offender).
While modernists may disagree and prefer to aspirate the h and thus favour ‘a historian’, if challenged by these dangerous revolutionaries, refer them to the above and the glorious roots of our language. Hold to traditions, abjure profane and unnecessary modernisms, and avoid aspirating the h when it should not be so pronounced.
‘An historian’ I was trained and ‘an historian’ I shall remain.
Good night and good luck.