。、。
We must learn to live together as brothers, or we will perish together as fools.
Literal
We [topic-は] brothers as together live thing [object-を] know-must. Otherwise, fools as together perish [conjecture-であろう].
A translation of Martin Luther King Jr.'s famous quote ('We must learn to live together as brothers or perish together as fools'). Several formal constructions: こと as nominalizer turning 'living together' into an object; ~として ('as X'); さもなくば ('otherwise,' a literary conjunction pairing with ~ば); and である (the formal/written copula), with the literary conjectural であろう ('will presumably be'). High register — not how anyone would speak casually.