fuller revision.

As pure literature, the _Nature of Things_ has all the defects
inseparable from a didactic poem, that unstable combination of
discordant elements, and from a poem which is not only didactic, but
argumentative, and in parts highly controversial. Nor are these
difficulties in the least degree evaded or smoothed over by the poet. As
a teacher, he is in deadly earnest; as a controversialist, his first
object is to refute and convince. The graces of poetry are never for a
moment allowed to interfere with the full development of an argument.
Much of the poem is a chain of intricate reasoning hammered into verse by
sheer force of hand. The ardent imagination of the poet struggles through
masses of intractable material which no genius could wholly fuse into a
metal pure enough to take perfect form. His language, in the fine
prologue to the fourth book of the poem, shows his attitude towards his
art very clearly.

_Avia Pieridum peragro loca nullius ante
Trita solo; iuvat integros accedere fontes
Atque haurire, iuvatque novos decerpere flores
Insignemque meo capiti petere inde coronam
Unde prius milli velarint tempora Musae:
Primum quod magnis doceo de rebus, et artis
Religionum animum nodis exsolvere pergo,
Deinde quod obscura de re tam lucida pango
Carmina, musaeo contingens cuncta lepore._

The joy and glory of his art come second in his mind to his passionate
love of truth, and the deep moral purport of what he believes to be the
one true message for mankind. The human race lies fettered by