In Sonnet 148, William Shakespeare develops the themes revisited with Sonnet 147 and further elaborates on his realisation that reason has abandoned him and he is therefore incapable of judging properly what he sees. Either that, or his eyes themselves are faulty, since they seem to distort what they are looking at.

The conclusion he comes to, much in line with the previous sonnet, is that his defective vision stems from his love for his mistress, but he here adds the almost 'technical' but for this not at all inconsequential detail that his eyes couldn't possibly be expected to deliver a true picture to the brain of what they see, since their vision is blurred by tears, suggesting therefore that this love he feels for his mistress is tinged with sadness, sorrow, or pain.

In Sonnet 147, William Shakespeare brings together two themes that have agitated him before: firstly the at the time fairly commonplace notion of love – and, more to the point, desire – as a disease that weakens the mind to the point of an irrational madness and afflicts the body in a similarly stark fashion, and secondly the ways in which his mistress deviates from the ordinarily praised ideal of beauty.

The sonnet therefore returns the series firmly and identifiably to the 'Dark Lady' and the effect she is having on our poet in an unequivocally physical manner, leaving behind the reflections on the soul of the previous sonnet and concerning itself once more with his lust for someone he knows – or at the very least declares – to be neither traditionally beautiful nor morally sound.

With his solemn, near pious, Sonnet 146, William Shakespeare for the first and only time speaks directly to his soul and entreats it to look after itself; to stop expending its energy on the pursuit of outward, physical adornments which are all doomed to swift decay – effectively starving and weakening itself whilst feeding and strengthening the gluttonous body that is only meant to house it and that will soon succumb to death – and to instead let go of material riches and with the 'return' from 'selling' them, 'purchase' something infinitely more valuable: eternal life in concord with, and on the terms ordained by, God.

The poem makes no mention, nor does it allude to or reference indirectly, any lover, mistress, or wife, nor love itself, or sex. This, too, makes it unique in the collection. As does its close alignment with a Christian notion of redemption through spiritual nurture at the expense of, and in preference to, physical or material gratification.

Sonnet 145 stands out in the collection for several reasons. Some factual, some conjectural, some somewhere in-between.

Most obviously and beyond interpretation evident is the fact that it is the only poem composed in iambic tetrameter: it consists of 14 lines of eight syllables each, in contrast to the iambic pentameters present in all the other sonnets, giving each line of those ten or eleven syllables.

Also still difficult to dispute, though already in the realm of opinion, is the observation, so as not to say contention, put forward by many scholars and commentators, that the sonnet is poetically, stylistically, literarily 'slight': it strikes a simple tone, uses some extremely familiar imagery and analogy, and is, as far as we can tell, mostly devoid of the high level compositional and rhetorical devices used in many of the other, 'regular', sonnets.
Pure supposition, though intelligent and fully valid as a suggestion, is the idea that the sonnet puns on the name Hathaway and is therefore not about the Dark Lady or any other mistress, but about Shakespeare's wife, Anne; and even more adventurous is the conjecture drawn from it that therefore the poem be an early stab of Shakespeare's at as-yet-imperfect sonneteering: there is absolutely no proof that this is so, and it is just as conceivable that Shakespeare with Sonnet 145 deliberately and most intentionally not only employs a different format but also aims for a categorically different tone.

With his exceptionally explicit and startlingly revelatory Sonnet 144 William Shakespeare addresses head on the fact that his mistress and his lover are certainly friends, and that he suspects – rather strongly, we get the impression – them to be so with benefits.

By identifying the man as 'right fair' and contrasting him with a woman who is 'coloured ill', he confirms what we have long thought to be the case: this is a constellation that has turned triangular, and it involves these precise three individuals, the poet, his younger male lover, the Fair Youth of the first 126 sonnets in the collection, and the Dark Lady around whom 25 of the remaining 28 sonnets revolve.

This rather puts paid to the suggestion espoused by some scholars that these sonnets can or let alone should be read in isolation, that no narrative of any kind should ever be deduced from them, or that they may have been written to and about any number of lovers of any gender over the period of their composition. What Sonnet 144 shows beyond anything that might still be considered reasonable doubt, and much in line with Sonnets 33 through 42 in the Fair Youth section and Sonnets 133 and 134 in this, the Dark Lady section of the collection, is that these two groups of poems overlap, that they concern themselves with the same 'two loves' of Shakespeare's, and that our poet is profoundly disturbed by the fact that, as he sees and presents it, his mistress has seduced his young man.

With his uncharacteristically lighthearted Sonnet 143, William Shakespeare plants a picture in our minds of the poet as a crying toddler placed on the ground while his mother is running after a wayward chicken, and expresses his hope, not unreasonable in the imagined circumstances, that the mother, once she has caught the bird she's chasing, will come back to him and comfort him with her affection and her love.
It's an unusual simile to say the least: not because it is complex or difficult to visualise – in fact the opposite – but because it departs from virtually all and any traditional or even just, one might argue, advisable comparison for a lover to invoke: rare is the Lothario who impresses his mistress by likening himself to her babe. And it continues to expressly accept the fact that this woman has other men whom she actively pursues. In this case, it would appear, one particular other man, who in this oddly farcical setup is assigned the role of the runaway cockerel.

With Sonnet 142 William Shakespeare picks up on the notion of 'sin' employed in the last line of the previous sonnet, and now juxtaposes this sin or sinful love of his for his mistress with her supposed 'virtue' in rejecting this love for being sinful, while simultaneously undermining any suggestion that she is in fact virtuous by asking her to just take a long, hard look at herself and her own behaviour, from which she will readily recognise that it is just as bad, if not in fact much worse.

The sonnet thus continues the poet's double-edged approach to wooing his mistress, by on the one hand expressing his wish to have sex with her, while on the other hand also mildly rebuking her for having sex with other men, or, to be more precise, while refusing to be rebuked by her for wanting to have sex with her, when she herself is liberally sleeping around.

Sonnet 141 is one of several poems in the collection that show William Shakespeare to be deeply ill at ease with his lust and his love for his mistress.

It may easily be argued that all of the Dark Lady Sonnets come over with a greater or lesser degree of ambiguity, with her appearance, her comportment, her smell, her touch, her sound, and most certainly her fidelity, all having either been brought into question or downright decried.

Sonnet 141 does all of the above, summarising these 'thousand errors' his mistress appears to possess and laying them out as a supposedly sensual feast, the like of which he has no appetite for. Yet he still finds his foolish heart drawn to her, and for this, he concludes, he must suffer the pain that he appears to accept as his – perhaps in a somewhat perverse way – due reward.