“What is your substance, whereof are you made”
"Substance" here carries a precise philosophical meaning: the essential nature or inner being of a thing, what something truly is beneath its outward appearance. The question is not casual flattery but a genuine puzzle — what kind of being can a person have that allows him to be reflected in everything beautiful?
“millions of strange shadows on you tend”
The whole sonnet is built on the philosophical pair 'substance' (the real thing) versus 'shadow' (a copy, reflection, or image). The beloved is the one true original; every beautiful thing in the world is only a shadow — an imperfect copy — that attends on him. "Strange" means belonging to other people, external or foreign. "Tend" means attend upon, as a servant waits on a master.
historical The sonnet form- TLN 733classical allusion
“Describe Adonis, and the counterfeit”
Adonis was the most beautiful youth in Greek myth — desired by the goddess Venus herself. Any painted or written portrait ('counterfeit') of him is only a poor imitation of the beloved, because the beloved is the original from whom Adonis's beauty was itself copied. 'Counterfeit' means a portrait or artistic likeness, not necessarily a fraud.
classical Venus and Adonis - TLN 735classical allusion
“On Helen's cheek all art of beauty set”
Helen of Troy was the classical standard of female beauty — the woman whose face, in Marlowe's phrase, launched a thousand ships. Here the poet imagines the beloved painted in Helen's clothing and jewels ('Grecian tires') and still recognizably himself, a new image of beauty. 'Tires' means ornamental headdresses or attire, especially as worn in classical dress.
classical Helen of Troy “Speak of the spring, and foison of the year”
'Foison' means abundant harvest, plenty — the rich yield of autumn as opposed to the budding of spring. The sonnet pairs two seasons: spring represents the beloved's beauty (fresh, bright, new), and the autumn harvest ('foison') represents his generosity or 'bounty.' Both are shadows of what he already is.
“you like none, none you, for constant heart”
This is the sonnet's volta — the turn that pivots the whole argument. External beauty (looks, grace) is shared with many things in nature; what belongs to the beloved alone is a 'constant heart,' meaning steadfast faithfulness. The chiasmic phrasing ('you like none, none you') doubles the claim for emphasis: nothing resembles him, and he resembles nothing, in this one respect.
historical The sonnet form