British Romantic thought are as follows:

1. In M. Waldman I found a true friend. His gentleness was never tinged by dogmatism; and his instructions were given with an air of frankness and good nature that banished every idea of pedantry. (Victor-Chapter 4)

This quote speaks to the nature of man. The nature of man is not created by man; instead, it is simply natural to be a certain way. Nature makes mankind like this.

2.  I revolved these circumstances in my mind, and determined thence forth to apply myself more particularly to those branches of natural philosophy which relate to physiology. (Victor-Chapter 4)

This quote shows the importance of the individual's mind. Nothing will keep Victor from succeeding at his task.

3.  One secret which I alone possessed was the hope to which I had dedicated myself; and the moon gazed on my midnight labours, while, with unrelaxed and breathless eagerness, I pursued nature to her hiding-places. Who shall conceive the horrors of my secret toil, as I dabbled among the unhallowed damps of the grave, or tortured the living animal to animate the lifeless clay? (Victor-Chapter 4)

Here, one can see nature's influence over Victor and his challenge. Only creating life will allow Victor to be satisfied.

4.  Get well--and return to us. You will find a happy, cheerful home, and friends who love you dearly. (Elizabeth- Chapter 6)

This quote exhibits Elizabeth's natural goodness.

5.  A selfish pursuit had cramped and narrowed me, until your gentleness and affection warmed and opened my senses; I became the same happy creature who, a few years ago, loved and beloved by all, had no sorrow or care. (Victor- Chapter 6)

This quote examples Clerval's natural goodness.

Romantic literature often focused on individualism, emotion, and a tortured hero who has broken the rules of society, God, or nature.

In chapter 5, Romanticism is expressed through the intense emotions of anguish and disgust Victor experiences upon seeing his creation. This sense of horror overwhelms him. As he puts it:

Sometimes my pulse beat so quickly and hardly that I felt the palpitation of every artery; at others, I nearly sank to the ground through languor and extreme weakness.

Shelley shows how deeply Victor feels the pain of having created a monster. His response is not rational, reasoned "what do I do now?" but a severe emotional reaction of distress.

Second, the chapter shows Victor, the isolated individual genius who has worked alone in his tower for several years to create life from inanimate parts, as the tortured hero. Like Prometheus, who was punished for taking on the privileges of the gods in giving fire to the humans, so has Victor overreached his human bounds. This is a very typical thing for a Romantic hero to do: such a hero often attempts to do more than mere mortals can achieve. Victor is punished and tormented for taking on the prerogative or privilege of God in creating human life.

Shelley also points specifically to Victor as a Romantic figure being punished for violating God's laws by quoting in this chapter from "The Rime of the Ancient Mariner," another Romantic work in which the protagonist, the Ancient Mariner, is punished for violating the laws of God and nature.

[eNotes editors are allowed to answer one question per posting. Each new question must be posted separately.]

Romanticism (in literature) arose in response to England's Industrial Revolution—mining destroyed the beautiful English landscape, and the Romantics sought to stop the destruction by promoting a return to nature. Romantics also idealized women and children—who were oppressed as workhouses provided them with much needed work, but under inhumane circumstances. There was the presence in the Romantics' work of melancholy, superstition, and the championing of personal freedom.

Dark Romanticism is also seen in specific writers whose work was closely identified with Gothic literature (such as Shelley).

Dark Romantics present individuals as prone to sin and self-destruction, not as inherently possessing divinity and wisdom.

In Chapters Seven and Eight of Mary Shelley's Frankenstein, there is the opposition to Victor's rejection of nature—when life should only be created by God, but Victor plays God and creates a monster that is not natural, but deadly. Victor's error is evident in creating a monster that first murders Victor's brother, William. Alphonse says:

About five in the morning I discovered my lovely boy, whom the night before I had seen blooming and active in health, stretched on the grass livid and motionless: the print of the murder's finger was on his neck.

(Nature: "blooming and active in health..."). Before Victor goes to his house, he rests, and nature comforts him:

...in this painful state of mind[,] I contemplated the lake: the waters were placid; all around was calm; and the snowy mountains, “the palaces of nature,” were not changed.

The creature is wise enough to know that planting evidence on the innocent Justine will convict her of the murder, leaving the creature free to do as he wishes.

I saw him too; he was free last night!”

"I do not know what you mean,” replied my brother..."but to us the discovery we have made completes our misery...Indeed, who would credit that Justine Moritz...could suddenly become capable of so frightful, so appalling a crime?”

Even Justine reports to the court:

I believe that I have no enemy on earth, and none surely would have been so wicked as to destroy me wantonly. Did the murderer place it there?

The creation of the monster arises from the advancements in medicine and science that provide a way to create a creature—this is also a criticism of the Industrial Revolution.

In terms of Dark Romanticism, the character "prone to sin" is primarily Victor—he "plays God" by creating a life. In doing so, he sets into action a series of events that will ultimately destroy his life as the creature kills Victor's loved ones to punish his creator. Victor does not show wisdom by his actions—simply misplaced intelligence. In Dark Romanticism...

...the natural world is dark, decaying, and mysterious; when it does reveal truth to man, its revelations are evil and hellish.

The natural world for Victor and his family has become dark and mysterious; death surrounds them. The revelations to Victor are evil and hellish, and these same thoughts must also come to each of the monster's victims the moment before they die at the creature's hands. The story is steeped in melancholy: Victor sees the innocent die for his actions.

William and Justine [were] the first hapless victims to my unhallowed arts.

Additional Source:

http://www.enotes.com/frankenstein-text/chapter-vii

Romanticism is a literary movement which is marked by several key components, many of which are observable in Mary Shelley's Frankenstein.

One element of Romanticism is the belief that imagination is able to lead to a a new and more perfect vision of the world and those who live in it. In this novel, Victor Frankenstein is the idealist who wants to create life from nothing; that is the ultimate ideal and marks victor as a Romantic. 

In another sense, Victor's actions demonstrate the Romantic renunciation of science and reason over emotion and nature.

So much has been done, exclaimed the soul of Frankenstein—more, far more, will I achieve; treading in the steps already marked, I will pioneer a new way, explore unknown powers, and unfold to the world the deepest mysteries of creation.

Victor's Romantic quest for the scientific ideal is paralleled by the monster's quest for an emotional connection both with other human beings and his environment.

Nature also plays a significant role in Romanticism and in this novel. Though it may not seem as prominent here as in other works, nature is a significant backdrop for Frankenstein. Victor does not give the monster life in Switzerland, where the winds are “but…the play of a lively infant”; instead the monster comes to life in the craggy, cold, and barren Orkneys. The consistent contrast between where Victor and his family live and where the monster lives adds to the monster's constant conflict with both man and nature.

While this novel is exemplary of the romantic period in that it uses a highly stylized and dramatized frame, more concerned with the realms of the fantastic than those of the real, the fantastic story becomes an allegory for very real emotions and struggles with which romantic writers were deeply preoccupied.

Even the title, Frankenstein; or, the Modern Prometheus, is a reference to a Romantic reliance on mythological allusions. Prometheus stole fire from the gods (he reached too far) and was punished for it, just as Victor overreaches by playing God and creating life and is them punished for it. 

Victor, especially after the creation of his creature, is especially alive to the sublimity of nature. Walton describes him to his sister, saying,

Even broken in spirit as he is, no one can feel more deeply than he does the beauties of nature. The starry sky, the sea, and every sight afforded by these wonderful regions seem still to have the power of elevating his soul from earth. Such a man has a double existence: he may suffer misery and be overwhelmed by disappointments, yet when he has retired into himself, he will be like a celestial spirit that has a halo around him [...].

The Romantics believed in the positive effects of nature, that it could restore one to one's best self and improve one's spirits. It can produce intense and wonderful feelings that inspire the viewer. Victor is so affected by nature, here as well as throughout the story, and this is one very significant way that we see the tenets of Romanticism appear in the novel. However, this quotation also elevates the individual human being almost to the divine. Romanticism championed the individual's abilities, imagination, powers of creation, genius, emotion, and growth. When Walton describes Victor as though he is some kind of holy spirit or angel, he acknowledges this very Romantic way of viewing the individual.

We see a similar focus on Victor's descriptions of Elizabeth. He tells Walton that, when Elizabeth was a child,

She busied herself with following the aerial creations of the poets; and in the majestic and wondrous scenes which surrounded our Swiss home—the sublime shapes of the mountains, the changes of the seasons, tempest and calm, the silence of winter, and the life and turbulence of our Alpine summers—she found ample scope for admiration and delight. While my companion contemplated with a serious and satisfied spirit the magnificent appearances of things, I delighted in investigating their causes.

Notice that Elizabeth is very much aligned with Romantic values while Victor seems to be characterized much more by Enlightenment ones. She wants to create while he wants to discover. It is not Elizabeth's values and priorities that jeopardize the lives of her friends and family; instead, it is Victor's that lead to the misery and ruination of so many. In this way, Shelley seems to champion Romantic values over Enlightenment ones: emotion over logic, fellow-feeling and empathy over science.

With her belief in the inherent decency of people, the Romanticist Mary Shelley wrote Frankenstein as a caution against what Wordsworth calls man's "meddling intellect." Although at times exaggerating them with Gothic elements, Shelley includes these Romantic elements in her novel: 

Feeling and Emotion are considered superior to intellect

The main conflict of the novel develops from the hubris of Victor Frankenstein who believes that he is capable of creating life.  While he does make a creature, his act of intellectual superiority leaves him bereft of family, loved ones, and friends.  Victor, like Walton who rescues him on the sea, lives in a selfish inner world.  Putting this hubris into words, Walton writes to his sister,

"I would sacrifice my fortune, my existence, my every hope, to the furtherance of my enterprise. One man's life or death were but a small price to pay for the acquirement of the knowledge which I sought, for the dominion I should acquire and transmit over the elemental foes of our race."

In contrast to this selfishness and intellectual rationalizations of Walton and Victor, the romanticized character of Elizabeth defends Justine's innocence at the trial for the death of Victor's brother William in spite of the fact that almost no one else will.  In addition, Elizabeth is willing to marry Victor despite dangers; always she loves others more than herself. Likewise, Henry Clerval "formed in the 'very poetry of nature,'" who hopes "to become one among those whose names are recorded in story as the gallant and adventurous benefactors of our species," is a loving friend to Victor, but in his selfishness of intellectual pursuit, Victor causes his death.  These characters of Elizabeth and Henry are portrayed as romantic heroes who value friendship and love over selfish intellectual endeavors.

There is an emphasis on the indvidual's experience

Throughout the narrative of Frankenstein, Shelley emphasizes the experiences of the innocent creature who is transformed by his treatment by Victor and society; for, his innate goodness is thrawted by the cruelty of his creator and other men.  Thus, he becomes the Romantic questing hero who seeks meaning and worth.  In the last chapter, he tells Walton how his love and sympathy have been "wrenched by misery" to vice and hatred, but it is a hatred by torture of his very soul.

There is an emphasis upon "the sublime"

The "sublime" is a thrilling emotional experience that combines such feelings as awe and horror.  For the creature, his life that he has compared to that of Adam in Chapter XIII and that Shelley herself likens to Prometheus, is one in which he has sought happiness, but feels instead "impotent envy and better indignation" that have rendered him thirsty for vengeance. To his horror, the creature tells Walton, "Evil thenceforth became my good."

Nature is revered

Nature is viewed as an oasis of peace and purity where people can be redeemed in the presence of a divine force.  When, for instance, Victor travels with Henry to Switzerland, he transcends for a time his selfish concerns. Of the "majestic mountains" and the Danube he comments,

...there is a charm... that I never before saw equalled....Oh, surely, the spirit that inhabits and guards this place has a soul more in harmony with man...

These are some of the Romantic characteristics of Frankenstein

Mary Shelley’s novel falls squarely within Romantic preoccupations about the solitary nature of the human soul, including the creative spirt or genius that drives people. These concerns are indicated by the subtitle of TheModern Prometheus. Victor Frankenstein, his creature, and Robert Walton each exemplifies in his own way this lonely, troubled genius. Frankenstein also exemplifies the Romantic glorification of nature and its inspiring, restorative force.

After Victor contemplates with horror his culminating achievement, the creature he has brought to life, he is seized with remorse. The emotion of isolation he had previously felt is further enhanced by his sense of guilt, which prompts him to flee from society.

I wandered like an evil spirit, for I had committed deeds of mischief beyond description horrible ... I had begun life with benevolent intentions, and thirsted for the moment when I should put them in practice, and make myself useful to my fellow-beings. Now ... I was seized by remorse and the sense of guilt, which hurried me away to a hell of intense tortures ... (Chapter 9)

Walton likewise feels deeply the harshness of a solitary existence, as he writes his sister:

I have one want which I have never yet been able to satisfy; and the absence of the object of which I now feel as a most severe evil. I have no friend, Margaret ... You may deem me romantic, my dear sister, but I bitterly feel the want of a friend. (Letter 2)

The creature, condemned by his liminal status, is even more solitary than either of the men. As he implores Victor, his creator, to welcome him with some show of affection, he emphasizes that he is essentially good as humans are. His use of “benevolent” echoes Victor’s words quoted above.

Believe me, Frankenstein: I was benevolent; my soul glowed with love and humanity: but am I not alone, miserably alone? (Chapter 10)

Nature is an inspiration and a healing force is shown by Victor’s recovery. As he regains his strength after the illness that acknowledging his failed experiment caused, he sets off on mountain “rambles” with his friend Henry. Soon, he feels almost like his old self.

... my health and spirits had long been restored, and they gained additional strength from the salubrious air I breathed ... happy, inanimate nature had the power of bestowing on me the most delightful sensations. A serene sky and verdant fields filled me with ecstasy. (Chapter 6)

As the creature is Victor’s alter ego, the type of natural landscape where he finds solace is likewise the opposite of the welcoming environment that inspires humans. The creature tells Victor,

The desert mountains and dreary glaciers are my refuge. I have wandered here many days; the caves of ice, which I only do not fear, are a dwelling to me, and the only one which man does not grudge. (Chapter 10)

One of the central aspects of the Romantic movement concerned man's relationship with nature, and in particular the way that nature represented balm to the soul of man and restored him to a right understanding of himself and the world. The Romantics saw in nature an untrammelled simplicity that was to be craved and that had been lost by so many through the Industrial Age and the focus on wealth, work, and the accumulation of property. This is why in this novel there are some fantastic descriptions of nature, all of which relate to Frankenstein's state of health, and Shelley shows how he finds restoration and healing from being in beautiful places. Note how Frankenstein described the healing impact of nature upon himself when he returns to Ingolstadt after achieving success in his goal of giving life to the creature:

When happy, inanimate nature had the power of bestowing on me the most delightful sensations. A serene sky and verdant fields filled me with ecstasy. The present season was indeed divine; the flowers of spring bloomed in the hedges, while those of summer were already in bud. I was undisturbed by thoughts which during the preceding year had pressed upon me, notwithstanding my endeavours to throw them off, with an invincible burden.

Nature is therefore shown to be successful where Victor, in spite of all his efforts, only failed. It restores him to the carefree individual he once was before he pledged himself to scientific discovery, and the sight of spring and summer in all of its glory fills him with "ecstasy." This highlights one of the central aspects of Romanticism which is the relationship between man and nature and the beneficial impact that nature has upon the human species.