The giant now awoke. The mind, never torpid, but never rouzed to its full energies, received the spark which lit it into an unextinguishable flame. Who can now tell the feelings of liberal men on the first outbreak of the French Revolution. In but too short a time afterwards it became tarnished by the vices of Orléans - dimmed by the want of talent of the Girondists - deformed and blood-stained by the Jacobins.
At one point in Shelley's novel the monster faces Victor on an icy glacier. The creature explains his feelings of isolation and abandonment. Victor still does not see he is the one that abandoned this creature, that he was the one responsible to love and devote his time to the creature, just as his parents had done for him as a child. Why is there such a detachment for Victor? Why does he not see himself as the parent? In the essay The Nightmare of Romantic Idealism the author states, "When Frankenstein becomes a father [â€¦], he conveniently forgets these duties of parents to their offspring [â€¦] the one quality he lacks as a creator is the quality he most praises his own parents for: 'the deep consciousness of what they owed towards the being to which they had given life.'" (Shelley 391) This author also states that "[by Frankenstein's] refusal to accept an adult role in life [â€¦] he retains [â€¦] the power to create. But at the same time, he is thoroughly irresponsible [â€¦] and lacks the courage to face up to the consequences of his deeds."(Shelley 391) These passages help explain Victors mind set toward his creation. Unfortunately, Victor's enchanted childhood didn't prepare him for the real world. He never had to grow up and take responsibility for his own actions. Frankenstein explores the relationship between creator and creation, and the universal need for love and acceptance from one's parents and society. Victor's rejection of his creation causes the monster to feel as an outcast, stirring anger and resentment in the creature, to which he reacts violently by murdering those whom Victor holds most dear, until the end when Victor dies himself and the monster leaves to kill himself.
Another prevailing theme of Frankenstein is loneliness and the effects that loneliness has on humans. This theme is explored through the thoughts and experiences of the three main characters: Walton, Frankenstein, and the monster. The theme was created most likely because Mary Shelley herself was quite depressed and lonely.The letters at the beginning of the story are full of Walton's feelings of loneliness as his great adventure begins to lose its luster and appeal. Victor experiences fear and anxiety throughout the book. In the beginning of the story, Victor's work separated him from his family. He spent many years in isolation. When his family and friends began to die later in the story these unhealthy feelings intensify. He said "This state of mind preyed upon my health, which had entirely recovered from the first shock it had sustained. I shunned the face of man; all sound of joy or complacency was torture to me; solitude was my only consolation - deep, dark, death-like solitude." Frankenstein demonstrated these same emotions when he said "Thus situated, employed in the most detestable occupation, immersed in a solitude where nothing could for an instant call my attention from the actual scene in which I was engaged, my spirits became unequal; I grew restless and nervous." The monster summarised how drastically his loneliness changed him when he said "I cannot believe that I am he whose thoughts were once filled with sublime and transcendent visions of the beauty and the majesty of goodness. But it is even so; the fallen angel becomes a malignant devil. Yet even that enemy of God and man had friends and associates in his desolation; I am quite alone." Shelley was obviously exploring this theme, as loneliness is a core motivation for her core characters.
In Nightmare: Birth of Horror, Christopher Frayling discusses the theme against vivisection expressed in the novel, since Shelley was a vegetarian. In Chapter 3 Victor writes that he "tortured the living animal to animate the lifeless clay."
In an emotional speech, the Creature enunciates its peaceful vegetarian dietary principles and inclusive moral code. "My food is not that of man; I do not destroy the lamb and kid to glut my appetite; acorns and berries afford me sufficient nourishment. My companion will be of the same nature as myself, and will be content with the same fare. We shall make our bed of dried leaves; the sun will shine on us as on man, and will ripen our food. The picture I present to you is peaceful and human." According to feminist vegetarian writer Carol Adams, the Creature's including animals in its moral code provides "an emblem for what it hoped for and needed - but failed to receive - from human society." 
Another theme found within the novel is religion. The comparison of the monster and Adam and Lucifer is prevalent through the novel. Whether it be the lines from Milton's Paradise Lost or from the Bible itself, the religious overtones are very clear. "Devil" in fact is the first words Victor utters to the creature.
Representing a minority opinion, Arthur Belefant in his book, Frankenstein, the Man and the Monster (1999, ISBN 0-9629555-8-2) contends that Mary Shelley's intent was for the reader to understand that the Creature never existed, and Victor Frankenstein committed the three murders. In this interpretation, the story is a study of the moral degradation of Victor, and the science fiction aspects of the story are Victor's imagination.
Another minority opinion is the recent claim by the literary critic John Lauritsen, in his 2007 book, "The Man Who Wrote Frankenstein", that Mary's husband, Percy Bysshe Shelley, was the author. Lauritsen's hypothesis is not given credence by major Mary Shelley scholars, but the book was enthusiastically praised by the critic Camille Paglia and criticised by Germaine Greer.
Charles E. Robinson, Professor of English at University of Delaware, half supports this debatable authorship in his 2008 edition of Frankenstein. Robinson revisted the manuscripts of Frankenstein and recognised Percy Shelley's assistance throughout those manuscripts.
Shelley intertwines her themes with passages like this: "To die so miserably; to feel the murderer's grasp! How much more a murderer that could destroy such radiant innocence! Poor little fellow! One only consolation have we; his friends mourn and weep, but he is at rest. The pang is over, his sufferings are at an end forever. A sod covers his gentle form, and he knows no pain. He can no longer be a subject for pity; we must reserve that for his miserable survivors(Chapter 7)."
The characters Elizabeth, Victor, Victor's father, and his monster go through feelings that they all in a sense go through at different times. This quote is an example where the death of William and the feelings of Elizabeth are portrayed. The same feelings can be said from the mouth of Frankenstein's monster directed toward himself. He wishes dearly that his life would not have begun and if it had, for him to have gotten a chance to feel love and pity. His sufferings on the other hand are contrasted to poor William. They will never end because of what he was created to be, a cure to the pain of others. The monster is the miserable survivor. In such light, Victor is a miserable survivor, and his father is also miserable for his son and the situations that come to past, so much so that it kills him in he end.
Initial critical reception of the book was mostly unfavorable, compounded by confused speculation as to the identity of the author. Sir Walter Scott wrote that "upon the whole, the work impresses us with a high idea of the author's original genius and happy power of expression", but most reviewers thought it "a tissue of horrible and disgusting absurdity" (Quarterly Review).
Despite the reviews, Frankenstein achieved an almost immediate popular success. It became widely known especially through melodramatic theatrical adaptations - Mary Shelley saw a production of Presumption; or The Fate of Frankenstein, a play by Richard Brinsley Peake, in 1823. A French translation appeared as early as 1821 (Frankenstein: ou le Prométhée Moderne, translated by Jules Saladin).
Frankenstein has been both well-received and disregarded since its anonymous publication in 1818. Critical reviews of that time demonstrate these two views. The Belle Assemblee described the novel as "very bold fiction" (139). The Quarterly Review stated "that the author has the power of both conception and language" (185). Sir Walter Scott, writing in Blackwood's Edinburgh Magazine congratulated "the author's original genius and happy power of expression" (620), although he is less convinced about the way in which the monster gains knowledge about the world and language. The Edinburgh Magazine and Literary Miscellany hoped to see "more productions from this author" (253).
In two other reviews where the author is known as the daughter of William Godwin, the criticism of the novel is an attack on the feminine nature of Mary Shelley. The British Critic attacks the novel's flaws as the fault of the author: "The writer of it is, we understand, a female; this is an aggravation of that which is the prevailing fault of the novel; but if our authoress can forget the gentleness of her sex, it is no reason why we should; and we shall therefore dismiss the novel without further comment" (438). The Literary Panorama and National Register attacks the novel as a "feeble imitation of Mr. Godwin's novels" produced by the "daughter of a celebrated living novelist" (414).
Despite these initial dismissals, critical reception has been largely positive since the mid-20th century. Major critics such as M. A. Goldberg and Harold Bloom have praised the "aesthetic and moral" relevance of the novel and in more recent years the novel has become a popular subject for psychoanalytic and feminist criticism. The novel today is generally considered to be a landmark work of Romantic and Gothic literature, as well as Science Fiction.