A man is dancing at the wedding of his only child. He’s a good dancer, but never before, and never again in his lifetime, will his dancing attain the grace and expressiveness it now displays. In fact, all his talents, capabilities and qualities are currently at their zenith: his mind is at its keenest, his loves and his hates are at their most passionate. Put a brush in his hand, and he’ll paint you a picture which exacts the utmost of his artistic potential.

The chassidic masters use this parable to demonstrate their definition of “joy”: joy is revelation. Joy unearths latent potentials no one even knew existed, and amplifies revealed potentials to levels no one ever thought possible. Joy is an effusion of self that spills over to places and achievements far beyond the soul’s natural horizons.

If joy is the revelation and expansion of the soul, then sorrow is a soul’s concealment and contraction. In sorrow the soul retreats, silencing all outward expression, shriveling to its narrowest sliver of selfhood.

Little wonder, then, that chassidic teaching frowns upon sadness. An old chassidic saying goes, “Sadness is not a sin, but its effect on the person is worse than any sin’s.” The soul was sent to this world not to be, but to do; not to merely exist, but to achieve. To retreat into the self is to reverse the flow of life.

And yet, there are times when we’re told to be sad. The daily recitation of the Shema at bedtime (keriat shema she’al ha-mitah) is one such occasion: the closing moments of the day are a time of self-examination, a time to experience regret and remorse over the day’s failings and missed opportunities. Once a month, on Erev Rosh Chodesh (“Eve of the New Moon”), the process is repeated on a larger scale, encompassing the month that is coming to a close. And then there are the annual fast days and “days of reckoning.” Currently we find ourselves in the most sorrowful period of the Jewish calendar, the “Three Weeks” that mourn the destruction of the Holy Temple in Jerusalem.

Because without these times of sorrow, our joy would flow false. The tiniest misalignment at the source would develop into a gross discrepancy further downstream, becoming more and more corrupt as it follows its uncorrected trajectory. Our lives would turn erratic and diffusive, eventually evaporating altogether. That is why it is crucial that, on occasion, we stem the flow, retreating back to the source to make the needed adjustments and revisions.

Of course, there’s always the danger that the withdrawal may become a vortex, the self a black hole sucking deeper and deeper in, allowing no escape. If joy has its hazards, sorrow is the more dangerous by far.

This, then, is the key: the proportion must be preserved—a daily hour, a monthly day, some twenty-odd days a year—and the sorrow confined within these bounds. It must remain an active seeking, never a passive sinking. And always, always must sorrow be permeated with an awareness of its purpose: to serve as a tool of joy.