Sections 54-56 of the poem express Tennyson’s central crisis of faith that resulted from Hallam’s death and from the scientific discoveries of his age that challenged traditional Christian beliefs.  Although Charles Darwin would not publish his work On the Origin of Species Through Natural Selection until 1859, geological discoveries (particularly the study of fossils) had already implied that the Earth was millions of years old (far older than Christian theologians had suggested) and that species existed before humans, evolved, and became extinct.  The concept of biological evolution had already been proposed by scientists (but it would be Darwin who would refine the concept and argue it most convincingly, causing the great religious crisis of the later half of the Victorian Age).  In Section 54 of Tennyson’s poem, the speaker expresses the doubt and the threat to traditional beliefs in divine order created by current scientific theories about life.  The speaker initially expresses his faith in life having a benevolent, divine purpose by claiming that although “we know not anything,” we can still “trust that good shall fall/ At last—far off—at last, to all.  And every winter change to spring” (lines 13-16).  However, his sense of loss ultimately makes him question his faith—the speaker’s belief in a purpose for life seems merely a “dream,” a hopefully fantasy, while his doubt makes him feel like an abandoned and confused child: “but what am I?/ An infant crying in the night;/ An infant crying for the light,/ And with no language but a cry” (lines 17-20).  In these lines, Tennyson evokes an image that would dominate much Victorian poetry dealing with the nineteenth century’s crisis of faith: the image of mournful wailing/crying for something lost (this motif reappears in “The Passing of Arthur”).
	In Section 55, the speaker examines the relationship between God, Nature, and humanity, and claims that God and Nature seem to be “at strife” (line 5).  The discovery of fossils of extinct species suggests that Nature is “so careful of the type” but “so careless of the single life” (lines 7-8); a “type” (a species) may evolve and progress, but individuals pass away.  While Judeo-Christian tradition has taught the speaker to believe in a benevolent God that values each human life as precious, callous Nature seems to have no care for the individual and brings death indiscriminately to all.  This “strife” between traditional concepts of God’s benevolent purpose and the tremendous, uncaring power of Nature implicit in biological evolution, causes the speaker to question his faith in a divine purpose in life (see lines 13-20)— “I falter where I firmly trod [his faith fails where previously he was secure]. . . .  I stretch lame hands of faith and grope, /And gather dust and chaff, and call/ To what I feel is Lord of all,/ And faintly trust the larger hope [he desperately tries to hold onto his faith in God’s higher purpose].”
	In Section 56, the speaker asserts that discoveries related to biological evolution (fossils found in “scarped cliff and quarried stone”) suggest that Nature ultimately cares no more for species than for the individual life.  Nature cries, “A thousand types [species] are gone;/ I care for nothing, all shall go” (lines 3-4).  Like individual lives, all species eventually pass away, including humans, the species that Judeo-Christian tradition teaches is specially created by a loving God for a “splendid purpose” (line 10).  But if humanity will also pass away, like all the preceding species that are now only fossils, what purpose is there in human life?  The speaker points out that man “trusted God was love indeed/ And love creation’s final law--/ Though Nature, red in tooth and claw/ With ravine, shrieked against his creed” [humanity believed in God’s loving purpose despite the cruelty of the natural world] (lines 14-16).  But if humanity will eventually die to “be blown about the desert dust, /Or sealed within the iron hills [as fossils],” then humanity is nothing more than a “monster, . . a dream, / A discord,” a life form without purpose.  The speaker asserts that if this is the case, life is meaningless: “O life as futile, then, as frail!/ O for thy voice to soothe and bless!” [he longs for the voice of his dead friend Hallam to comfort him in the face of his loss of faith] (lines 25-26).  But the speaker does not abandon all hope.  He concludes by asking if there is any “hope of answer” to this dilemma of faith and concludes by claiming that the answers lie hidden “Behind the veil, behind the veil” (lines 27-28).  These final lines suggest that a greater purpose in life may still exist but may be temporarily hidden from us; therefore, faith may still be possible.