David is lifted on and on by a continuous tide of illuminating thought,
perfectly new and strange, but to which nothing in him opposes the
semblance of resistance, Karshish feels only a mysterious attraction,
which he hardly confesses, and which all the intellectual habits and
convictions of a life given up to study and thought seem to gainsay. No
touch of worldly motive belongs to either. The shepherd-boy is not more
single-souled than this devoted "picker up of learning's crumbs," who
makes nothing of perilous and toilsome journeys for the sake of his art,
who is threatened by hungry wild beasts, stripped and beaten by robbers,
arrested as a spy. At every step his quick scrutiny is rewarded by the
discovery of some new drug, mineral, or herb,--"things of price"--"blue
flowering borage, the Aleppo sort," or "Judaea's gum-tragacanth." But
Karshish has much of the temper of Browning himself: these
technicalities are the garb of a deep underlying mysticism. This man's
flesh so admirably made by God is yet but the earthly prison for "that
puff of vapour from his mouth, man's soul." The case of Lazarus, though
at once, as a matter of course, referred to the recognised medical
categories, yet strangely puzzles and arrests him, with a fascination
that will not be put by. This abstracted docile man of perfect physical
vigour, who heeds the approach of the Roman avenger as he would the
passing of a woman with gourds by the way, and is yet no fool, who seems
apathetic and yet loves the very brutes and the flowers of the
field,--compels his scrutiny, as a phenomenon of soul, and it is with
the eye of a psychological idealist rather than of a physician that he
interprets him:--

"He holds on firmly to some thread of life-- ...
Which runs across some vast distracting orb
Of glory on either side that meagre thread,
Which, conscious of, he must not enter yet--