"There was thick darkness over the entire land of Egypt for three days. [One Egyptian] did not see his brother, and no one rose from his place for three days, but for all the children of Israel there was light in their dwellings" -- Exodus 10:22-23.

As opposed to the other nine plagues which afflicted the Egyptians in a very practical way, each causing catastrophic personal and/or property damage, the Plague of Darkness didn't cause any tangible harm.

The absence of light merely denies people the ability to see their surroundings, making it impossible to discern objects or people in their vicinity. Though humans are endowed with another four senses, each providing the ability to become somewhat familiar with one's surroundings, none are as critical as sight. Lack of sight is such a major impediment that our sages tell us that to a certain degree a sightless person is considered to be lifeless.

Why is light - and the faculty of sight that it enables - so crucial? Two answers come immediately to mind, one practical and one psychological:

1) We are surrounded by items designed to improve our lives. Without light, however, the most helpful of implements is reduced to a mere obstacle. A chair, a table, or a mountain of gold for that matter, will trip up the person who walks in darkness.

2) Light motivates to action, as opposed to darkness which breeds depression and lethargy. The bright environment created by light allows people to rise above their self-centered tendencies and truly empathize with others.

The Plague of Darkness which struck the Egyptians was a physical reflection of the their sorry spiritual state. The Israelites didn't suffer from the plague, because their light was provided for by Torah and mitzvot -- "A mitzvah is a candle and Torah is light" (Proverbs 6:23).

With the benefit of the illumination provided by Torah and its commandments, an entire new world comes to light. Suddenly, those things which one considered to be obstacles are revealed for what they really are -- creations of G‑d, intended to assist in one's spiritual journey. The piles of gold are revealed before the mind's eye.

And the darkness which pervaded the Egyptian society didn't allow them to "rise from their place"; they were mired in their own selfish desires and pursuits and couldn't envision a higher goal. Worse yet, they "could not see their brother," their selfishness precluded them from sharing in the joy of a friend or commiserating with him or her in a time of distress.

It is in our hands to brighten our lives; we were given the tools. And when we manage to live in light despite the darkness that surrounds us, that is a sure indication that the redemption - both personal and national - is just around the corner.

Why?

Because what is our current exile state, galut, if not a thick darkness that obscures the truth? When we successfully claw away the darkness, the light that emerges is a portent for the time when darkness will be banished forever, when all of creation will finally see what it's all about.