The word theme comes from the Ancient Greek word théma, which means “proposition or thesis,” and that definition essentially holds true to this day:
Theme is meaning.
In literature, it’s the meaning that the events of a story or the lines in a poem add up to.
For example, and as I’ve written before, the theme of the movie Rocky is: the triumph of the human spirit, even in the face of great odds.
I mention Rocky again now because I recently rewatched both it and also the movie The Wrestler — a fairly well-acted and well-made movie directed by Darren Aronofsky — and I’m more convinced than ever that The Wrestler was strongly influenced by Rocky. And yet, despite being similar in plot and subject-matter, they are diametrically dissimilar thematically:
The theme of The Wrestler is one of pure fatalism, even nihilism, as Darren Aronofsky’s movies often are.
Because his themes, as everyone’s themes, are a mirror and extension of the ideas he holds.
Where do themes come from?
Yes, themes come from ideas — specifically, the ideas which the artists holds with enough conviction to create an entire work of art around — and this is why all themes are not equal: because all ideas are not equal.
Far from it, in fact:
The ideas that made Ancient Greece one of the greatest civilizations in human history are, for instance, vastly different from — and vastly superior to — the ideas that shaped the National Socialism of NAZI Germany. Both of these cultures (as all cultures) sprung directly from the ideas at their foundation.
And just as the ideas that each individual holds shape each individual, so the ideas that dominate a given society shape that society. The reason this is so is that humans are a conceptual species: we survive primarily by means of our reasoning brains — i.e. we think — and ideas are thoughts. Thus ideas are the quiddity of the human faculty of reason.
The following is Sonnet 94, by Shakespeare, which is a much more complex poem than it may at first appear — containing as it does numerous interwoven metaphors, as well as a devilishly sophisticated sentence structure (note that the first eight lines are one long sentence, and that the entire sonnet consists only of two total sentences: pitch-perfect, well-claused, beautifully punctuated):
They that have power to hurt and will do none,
That do not do the thing they most do show,
Who, moving others, are themselves as stone,
Unmoved, cold, and to temptation slow:
They rightly do inherit heaven’s graces
And husband nature’s riches from expense;
They are the lords and owners of their faces,
Others but stewards of their excellence.
The summer’s flower is to the summer sweet
Though to itself it only live and die,
But if that flower with base infection meet,
The basest weed outbraves his dignity:
For sweetest things turn sourest by their deeds;
Lilies that fester smell far worse than weeds.
Though deciphering the theme of this poem requires a close reading and rereading, I believe the subject-matter can be found in the opening line:
They that have the power to hurt and will do none
The following seven lines are an intricate pattern of metaphors which build upon the opening:
“moving … are as stone … unmoved, cold …. inherit heaven’s graces … husband nature’s riches from expense …. lords … owners of their faces [i.e. their expressions and perhaps their beauty] … stewards.”
It is, in my opinion, easy to take for granted such dazzling linguistic virtuosity, as, at age 19 and reading it for the first time, I myself once did. Now, however, I grasp how challenging it is to put down lines like that — such apposite and careful metaphors written with such lapidary eloquence, and in such perfect and strict syllables and rhyme.
There is little question in my mind that “to temptation slow” is an oblique allusion to the biblical “slow to speak and swift to hear.”
The second sentence beginning at line 9 introduces a new metaphor, which does not contradict but elaborates the metaphors he’s already inlaid — specifically “The summer’s flower.”
In a way, the summer’s flower is the subject of the entire third quatrain.
The closing couplet then unites the two sentences — and the metaphors — and it’s been observed that that closing couplet (which incidentally also appears in The Reign of King Edward III,  which is NOT a Shakespearean play, though many scholars have detected Shakespeare’s hand in it) is an Elizabethan recasting of the well-known Latin apothegm:
Optima corrupta pessima.
“The best become the worst when corrupted.”
Observe also that Shakespeare does not in this sonnet use any personal pronouns — I, me, or thou — as he often does use them. I believe this is deliberate and goes to his “unmoved” metaphors and his theme. I believe also that it is ambiguous whether in this poem Shakespeare regards being “unmoved” and “cold” as an entirely good thing or a bad thing. As one scholar put it:
“Perhaps Shakespeare is unable to bear the thought of his fair subject as baser than ‘the basest weed.'”
I like that interpretation and find it authentic and touching.
Other close readers have detected a certain irony or even disdain in some of Shakespeare’s language here — for example, line 7:
“lords and owners of their faces”
Which might be interpreted as possibly hinting at a kind of duplicity or deceptiveness, “a mismatch between the faces they put on and that which lies within.”
I myself have always found this particular line — and the choice of the word “faces” primarily — the most interesting and cryptic lines in the poem.
There is also, perhaps, a certain negativity directed toward “the flower” — surely a symbol of the one he loves — the flower that “to itself only live and die…”
But is this saying that the flower is only concerned with itself in an unhealthy way?
Or is he, rather, suggesting that the flower by its nature cannot be kind or compassionate or empathetic, but is condemned (by its very nature) to the kind of coldness of those discussed in the third and fourth lines?
Or is he, as I actually think, saying that the flower is nothing to itself — it’s above such considerations — though to the summer it is very sweet indeed?
Frank Kermode, an excellent Shakespearean, wrote that “Sonnet 94 may be a riddle of sorts, the answer being a charge against the fair lord for having committed such deeds as have made him the sourest of all.”
I think this is smart. I also think it’s intriguing. But in the final analysis, I don’t think it’s accurate.
I think the theme of this beautiful poem is at once simpler, in its elegant sophistication, and also more profound:
Humans are shaped by their deeds, which are shaped by their ideas.
Humans are the product of their theme.