To love that well (12): The meaning of this phrase and of the concluding couplet has caused much debate. Is the poet saying that the young man now understands that he will lose his own youth and passion, after listening to the lamentations in the three preceding quatrains? Or is the poet saying that the young man now is aware of the poet's imminent demise, and this knowledge makes the young man's love for the poet stronger because he might soon lose him? What must the young man give up before long -- his youth or his friend? For more on this dilemma please see the commentary below.
_____
Sonnets 71-74 are typically analyzed as a group, linked by the poet's thoughts of his own mortality. However, Sonnet 73 contains many of the themes common throughout the entire body of sonnets, including the ravages of time on one's physical well-being and the mental anguish associated with moving further from youth and closer to death. Time's destruction of great monuments juxtaposed with the effects of age on human beings is a convention seen before, most notably in Sonnet 55.
The poet is preparing his young friend, not for the approaching literal death of his body, but the metaphorical death of his youth and passion. The poet's deep insecurities swell irrepressibly as he concludes that the young man is now focused only on the signs of his aging -- as the poet surely is himself. This is illustrated by the linear development of the three quatrains. The first two quatrains establish what the poet perceives the young man now sees as he looks at the poet: those yellow leaves and bare boughs, and the faint afterglow of the fading sun. The third quatrain reveals that the poet is speaking not of his impending physical death, but the death of his youth and subsequently his youthful desires -- those very things which sustained his relationship with the young man.
Throughout the 126 sonnets addressed to the young man the poet tries repeatedly to impart his wisdom of Time's wrath, and more specifically, the sad truth that time will have the same effects on the young man as it has upon the poet. And as we see in the concluding couplet of Sonnet 73, the poet has this time succeeded. The young man now understands the importance of his own youth, which he will be forced to 'leave ere long' (14).
It must be reiterated that some critics assume the young man 'perceives' not the future loss of his own youth, but the approaching loss of the poet, his dear friend. This would then mean that the poet is speaking of his death in the literal sense. Feuillerat argues that
Even if we make allowance for the exaggeration which is every poet's right, Shakespeare was not young when he wrote this sonnet. It is overcast by the shadow of death and belongs to a date perhaps not far from 1609. (The Composition of Shakespeare's Plays, p. 72)
This interpretation is less popular because it is now generally accepted that all 154 sonnets were composed before 1600, so Shakespeare would have been no older than thirty-six. However, the sonnets were not initially printed in the order we now accept them, and an error in sequence is very possible.
Sonnet 73 is one of Shakespeare's most famous works, but it has prompted both tremendous praise and sharp criticism. Included here are excerpts from commentaries by two noted Shakespearean scholars, John Barryman and John Crowe Ransom: