In the Pictorial Key
, Waite says of Temperance: "A direct path goes up to certain heights
on the verge of the horizon . . ."
And for the Fool he says: ". . . a young man in gorgeous vestments pauses at the brink of a precipice among the great heights
of the world . . ."
It's as if the Fool has now reached the "certain heights" of Temperance. The height is of this world as Waite's description of Temperance suggests: "Hereof is some part of the Secret of Eternal Life, as it is possible to man in his incarnation
. Also, it's on the boundary of the horizon, though the suggestion is that it goes further.
The suggestion of the Fool is that he is also in his physical incarnation. He's among the great heights, but it's the heights of the world
. He's on the brink, or threshold, suggested at the end of the path in Temperance, poised to leap.