In Charles Dickens’s A Christmas Carol, Scrooge is visited by three spirits who will teach him to mend his avaricious ways before it is too late. The second spirit comes in the form of a “a jolly Giant, glorious to see.” This spirit introduces himself as the Ghost of Christmas Present. The spirit takes Scrooge to observe the Christmas that his clerk, Bob Cratchit, shares with his large family. It is a meager Christmas, as they cannot afford a lavish dinner. However, it is also evident that the Cratchits are a loving family, and that makes their Christmas holiday warm and lovely. Scrooge also observes Tiny Tim, who is very ill. Scrooge realizes that Bob’s son is in poor health and needs medical attention that the Cratchits cannot afford.

The spirit then takes Scrooge to observe the holiday celebration at his nephew’s house. This drives home the knowledge that Scrooge has a family, but he chooses to ignore them in the pursuit of his one passion: earning money. He also chooses to ignore them on Christmas. The nephew observes that Scrooge “loses some pleasant moments” by not celebrating with them.

The spirit then shows Scrooge two children who emerge from the spirit's robe. They are described in words that convey how awful they are. Specifically, they are “wretched, abject, frightful, hideous, miserable.”

The spirit orders Scrooge to look at the children. When he does, Scrooge realizes that

they were a boy and girl. Yellow, meagre, ragged, scowling, wolfish; but prostrate, too, in their humility. Where graceful youth should have filled their features out, and touched them with its freshest tints, a stale and shrivelled hand, like that of age, had pinched, and twisted them, and pulled them into shreds.

Everything that one imagines about innocent children is lacking with these two. They are not like angels; instead, “devils lurked” in connection with them. Dickens spares no negative descriptive phrases to convey how horrible these children are. He writes,

No change, no degradation, no perversion of humanity, in any grade, through all the mysteries of wonderful creation, has monsters half so horrible and dread. Scrooge started back, appalled.

The spirit explains that these children are Mankind’s children: Ignorance and Want. In other words, this is the human condition that befalls many unfortunate people. Many are ignorant, as Scrooge is. The spirit expressly tells Scrooge to be particularly wary of Ignorance, as Scrooge’s life is characterized by ignorance. He is ignorant of the pleasant ways of people around him, such as his nephew and Bob Cratchit. He is ignorant of how to behave to people and how to help them whenever he can. In short, he is ignorant of how to be a good person. As a result of ignorance, many people live in horrible conditions and want for their very food and warmth. Although not quite at this level, Bob Cratchit’s family certainly wants for more sustenance than they can afford on the meager wages that Scrooge pays, which is one of the lessons this spirit tries to teach Scrooge.

In Stave 3, "The Second of Three Spirits," of A Christmas Carol by Charles Dickens, Ebenezer Scrooge and the Ghost of Christmas Present have just left a children's Twelfth Night party—which signifies the end of the twelve-day Christmas season of the Victorian period—when Scrooge notices two things about the Spirit. The first is that the Spirit has aged noticeably in the few hours that they've been together. "Are spirits’ lives so short?” Scrooge inquires of the Spirit. The Spirit responds that his life on earth is very short. “It ends to-night... at midnight,” the Spirit says, barely fifteen minutes from that moment.

The second thing that Scrooge notices about the Spirit is what Scrooge describes as "a foot or a claw" protruding from underneath the Spirit's robe. The Spirit opens his robe to reveal two wretched children, a boy and a girl. The Spirit identifies the boy as "Ignorance" and the girl as "Want," or poverty.

The children kneel down at the Spirit's feet, clutching at his robe while the Spirit reproaches mankind—represented by Scrooge himself—and most particularly Victorian society and its upper classes for allowing creatures such as these to exist.

The Spirit metaphorically compares the boy, Ignorance, to the "Doom" that he warns Scrooge awaits Victorian society and mankind if widespread ignorance isn't addressed and corrected.

Throughout his adult life, Dickens advocated for social reforms, including universal education, aid for the poor, the repeal of the Poor Laws, and the elimination of debtor's prisons, treadmills, and workhouses. Dickens used his novels, stories, and other writings to forward his progressive social agenda.

In A Christmas Carol, for example, Dickens directly addresses all of these issues and takes the Victorian upper classes to task for their inaction and their lack of will to initiate and support reforms to eliminate or, at the very least, reduce social injustice, particularly the ignorance and poverty so prevalent in Victorian society at the time Dickens wrote A Christmas Carol.

Near the end of Scrooge's time with the Ghost of Christmas Present, the ghost moves the folds of his robe aside to show Scrooge two children underneath.  He says,

They are Man's [...].  And they cling to me, appealing from their fathers.  This boy is Ignorance.  This girl is Want.  Beware them both, and all of their degree, but most of all beware this boy, for on his brow I see that written which is Doom, unless the writing be erased.

They are young, but instead of being beautiful and innocent and fresh, they seem pinched and shriveled as though they were much older.  Instead of the dewy, beatific faces of angels, the children glare out at Scrooge like devils, quite threateningly.  These are the two social evils that Dickens felt threatened humanity's future.  Want, the girl, could be interpreted either as greed, the greed of people like Scrooge, or as a representation of those who suffer as a result of their poverty, those who are actually in need. 

The boy, Ignorance, could likewise be interpreted in a couple of ways: he could symbolize the lack of education that can sometimes lead to poverty or he could symbolize the kind of ignorance that Scrooge claims, the ignorance that he uses to excuse himself from helping the less fortunate.  When the men came to collect for the poor at the beginning of the book, for example, they told Scrooge that many of the poor would rather die than go to the workhouses and such.  Scrooge responded that he "[didn't] know that."  He claimed ignorance to what the poor faced because, as he says,

It's not my business [...].  It's enough for a man to understand his own business, and not to interfere with other people's.  Mine occupies me constantly.

Scrooge purposely maintains his ignorance of the needs of others, and this kind of ignorance is incredibly dangerous for society. 

In A Christmas Carol by Charles Dickens, near the end of the second spirit's visit, two children emerge from beneath the folds of his robe. Scrooge asks about them because he sees something under the robe, and the Ghost of Christmas Past reveals them. 

"From the foldings of its robe, it brought two children, wretched, abject, frightful, hideous, miserable." (Dickens 85)

Dickens goes on to describe them as a boy and a girl.

"Yellow, meager, ragged, scowling, wolfish; but prostrate, too, in their humility. Where graceful youth should have filled their features out, and touched them with its freshest tints, a stale and shriveled hand, like that of age, had pinched and twisted them, and pulled them into shreds." (Dickens 86)

The children represent "Ignorance and Want." Dickens is bringing home the point that when society does not educate its youth, nor take care of its poorest citizens, society is doomed. When Scrooge asks if they have no help, the Ghost of Christmas Past returns Scrooge's own words to him,

"'Are there no prisons? Are there no workhouses?" (Dickens 87)

In doing so, he reminds Scrooge that he is part of the problem. Scrooge would rather people be thrown into prison than give them charity.