If eternal return is the heaviest of burdens, then our lives can stand out against it in all their splendid lightness.

If every second of our lives recurs an infinite number of times, we are nailed to eternity as Jesus Christ was nailed to the cross. It is a terrifying prospect. In the world of eternal return the weight of unbearable responsibility lies heavy on every move we make. That is why Nietzsche called the idea of eternal return the heaviest of burdens (das schwerste Gewicht).

Conversely, the absolute absence of a burden causes man to be lighter than air, to soar into the heights, take leave of the earth and his earthly being, and become only half real, his movements as free as they are insignificant.

But is heaviness truly deplorable and lightness splendid?

The heaviest of burdens crushes us, we sink beneath it, it pins us to the ground. But in the love poetry of every age, the woman longs to be weighed down by the man's body. The heaviest of burdens is therefore simultaneously an image of life's most intense fulfillment. The heavier the burden, the closer our lives come to the earth, the more real and truthful they become.

Parmenides responded: lightness is positive, weight negative. Was he correct or not? That is the question. The only certainty is: the lightness/weight opposition is the most mysterious, most ambiguous of all.

What then shall we choose? Weight or lightness?

Parmenides posed this very question in the sixth century before Christ. He saw the world divided into pairs of opposites: light/darkness, fineness/coarseness, warmth/cold, being/non-being. One half of the opposition he called positive (light, fineness, warmth, being), the other negative. We might find this division into positive and negative poles childishly simple except for one difficulty: which one is positive, weight or lightness?