William Shakespeare lived in an age of uncertainty. His society was traversing a number of unpredictable challenges that spun from the succession of the heirless queen Elizabeth to the ascent of a new class of merchants. But the biggest issue had to do with religious conflicts. In the premodern world, religion provided absolute certainty: whatever we knew was implanted in our mind by God. We didn’t have to look any further. Once that system of beliefs started to collapse, Europe was left with a yawning gap. Religion no longer seemed capable to explain the world. René Descartes and Shakespeare, who were contemporaries, gave opposite answers to the sceptical challenge: Descartes believed that our quest for knowledge could be rebuilt and founded on indubitable certainties. Shakespeare, on the other hand, made uncertainty a leitmotiv of all his works, and harnessed its creative power.
There is a tide in the affairs of men.
Which, taken at the flood, leads on to fortune;
Omitted, all the voyage of their life
Is bound in shallows and in miseries.
On such a full sea are we now afloat,
And we must take the current when it serves,
Or lose our ventures.
Brutus and Cassius are discussing the final phase of their civil war with the forces of Octavian and Marcus Antonius. Cassius has been urging that they group their forces at Sardis and take advantage of the secure location to catch their breath. Brutus, however, advocates heading off the enemy at Philippi before Octavian can recruit more men. Brutus's main point is that, since "the enemy increaseth every day" and "We, at the height, are ready to decline" (lines 216–217), he and Cassius must act now while the ratio of forces is most advantageous. "There's a tide in the affairs of men," he insists; that is, power is a force that ebbs and flows in time, and one must "go with the flow." Waiting around only allows your power to pass its crest and begin to ebb; if the opportunity is "omitted" (missed), you'll find yourself stranded in miserable shallows.
Ye have no time but this present time, therefore prize your time, for your soul’s sake.