The first stanza of "Blowin' in the Wind" sets a pattern—a pattern about patterns, if you will. This is a song about a big mystery: why do people keep killing and oppressing each other, even though anyone can see that war and injustice are terribly wrong? The song's repetitions speak to the bewildering perpetuation of human evil.
The speaker begins by setting a pattern of rhetorical questioning, asking huge, unanswerable questions. These questions aren't just the same in flavor, but also in their phrasing: their parallel structure means that each question starts with "How many" and comes to a central turning point at the word "Before":
How many [...] must [...]
Before [...]
The speaker begins by asking: "How many roads must a man walk down / Before you call him a man?" That's an internal question, dealing with personal choices. Those symbolic "roads" (representing journeys, choices, and life experiences) suggest the emotional exploration that might bring this "man" to maturity. In other words, how many things does someone have to experience or go through before they're considered an adult, taken seriously, granted respect, treated as a full human being?
The next question broadens out to a wider world, asking: "Yes, 'n' how many seas must a white dove sail / Before she sleeps in the sand?" In this line, made quiet and gentle by soft sibilant /s/ sounds, the speaker uses the dove, an ancient symbol of peace, to evoke a long (and ongoing) journey toward world peace. In the biblical story of Noah's Ark, Noah sends a dove in search of dry land; it returns bearing an olive branch. Here, the implication is that this dove will have to fly over many seas before being able to rest on dry land. On a symbolic level, this means that peace may be a long time coming. (See the "Symbols" section of this guide for even more on the dove.)
The speaker builds on the established pattern even further in his next question: "Yes, 'n' how many times must the cannonballs fly / Before they're forever banned?" This question relates to war—and war that's been going on for centuries, judging by those old-fashioned "cannonballs." The speaker is asking, how many wars do people have to have before they stop fighting and/or creating such deadly weapons?
This question also builds on the questions that came before it. Just as the white dove must "sail" over the sea, cannonballs "fly" over the land. The image of these weapons of war flying near that lovely dove is a frightening one, one that suggests human beings threaten to destroy any hope for peace through their repeated turn to war and violence.
The speaker's huge symbols—roads, doves, seas—give the song a feeling of grand scale. These questions are broad and general, to do with everyone. But do they have answers?