If this is for an art assignment or project for school or university you need to compare these images with reference to

artistic style
frames of reference
subject matter
the symbols/themes/imagery

Style and subject matter

- both are classic paintings
- both use realistic technique to show details of characters and scenes
- both use correct proportion and no use of abstract style or media
- different in that top image uses dark space to carry the style and point of view of the viewer, the top image focus is on the sleeping woman ( that's a demon on her chest giving her nightmares ). the top image is showing a relaxed and unreal scene. The woman is the focus and the demon represents her dreams/desires etc.
- bottom image is more realistic style, focus is on the males and their preparing for battle. The people in the background are showing real grief ( not a dream ) because they know their men could die fighting, they are the protectors in this image.

Frames and themes

- both use ancient imagery to represent themes within the artwork ( demons, swords, Roman soldiers )
- both use muted colors and characters to create realism
- both would have been used to represent the male and female forms

- different because the top image represents females - demons - unreality. We are suppose to believe the sleeping woman is at the mercy of the demon on her chest. In old times demons gave people bad dreams and made them do things they shouldn't. The woman looks to represent female sexuality and how this is beyond her control - she is weak
- the bottom image shows the male form, its strength, its reliance on weapons, the comrades in arms and we see them as protectors and strong.

And since you wanted a short answer I'll leave it at that :)

Ok, here goes. Before the contextual analysis, some history (so at least you know I'm not guessing entirely). The top piece is Gothic master, Fuseli's best known work and is called "The Nightmare". Fuseli was an ordained minister oddly enough, and as such dealt with a wide variety of reports from women who were demonized in the night and the pattern of sorts was that they usually slept alone and the paranormal assaults were usually of a sexual nature. So there you have, in the piece, a lone woman, posed in a sensual state, obviously unconscious. The somewhat freaky Incubus hanging out on her torso is turned, as if startled, by the person observing the painting. It's a horror show of the strangest kind because the demon isn't freaked out any more than a dog guarding it's territory. He might be more afraid of you than you are of him, or not. The mare to the left is another matter. That thing is, to me the oddest part of this piece. One can't help but wonder if, since Fuseli titled the piece "The Nightmare" if he didn't put the mare in it at night just for laughs. The backstory to this piece is a wild mystery with as many plot twists as you can speculate. One theory of the meaning of the piece is that it has to do with love. Shortly before he painted "the Nightmare" Fuseli fell crazy in love with a woman named Anna Landholdt and proposed. Her father disapproved and the wedding never happened. So some say that the demon is Fuseli and the woman is Anna. True? If it is, he didn't think much of himself or his horse. Who knows? It would be nice to ask him, but he never provided a single commentary on this painting, and he did this piece in 1781. Which brings me to one of just a couple of historical similarities between the pieces.

Three years later in, 1784, Jacques-Louis David completes "Oath of the Horatii", the painting below. It hangs in the Lourve and it's HUGE. We're talking like 10.5 feet by 14 feet. Both of these pieces are masterworks of Neoclassicism even though the Gothic art crowd has adopted Fuseli's "Nightmare" but, hey, it's just as historical as David's piece because David's piece never actually happened either. One's paranormal fiction, the other is historical fiction. A cool factoid about the Oath is that it was commissioned by King Louis XVI of France and during it's production, David actually lived in the Louvre, which was a huge deal. While he's living there, he meets Pecoul, who actually built the Louvre, and marries his daughter. Pointless but interesting, I guess demonstrating how art (or the process of creation) can affect the affairs of a life. The king was pretty stoked about the piece because of its political nature, and here's the disturbing reality as to why. As you can imagine, in those days when there were only three major networks and most folks barely had basic cable, the storyteller gathered a crowd and got the seat closest to the fire. And this painting told a fascinating (albeit fictitious) story of three members of the Horatius family (Romans) who were pitted in a duel against three members of the Curiatii family from the rival city of Alba Longa. Dad's remorseless visage is an important point in communicating the stoic mindless loyalty to the state but the drama is with the women. As the story goes, one of these women is a sister of the Curiatii but is married to one the Horatii, the plot thickens when it's told that one of the women who is a sister of (bet you didn't see this coming) the Horatii is engaged to one of the Curiatii. Family ties be put asunder to defend the honor of the state. And that's the point. A beautiful piece of art propagandized to betroth the loyalty of the people to King and State above all else. Political history buffs may clash with art historians over this, until you look at the timeline and realize that only five years later the French Revolution would rock the nation and this piece and story would play an important part in influencing a series of art that encouraged loyalty to the state above faith and family.

Now the fun part. To compare, two neoclassical oil paintings completed three years apart.... Each features women in some state of distress. To contrast, let's consider the theory that in "the Nightmare", Fuseli is the demon, his loyalty (for better or for worse) is obviously toward the woman. I mean, he's paying no attention to his horse at all. But in the "Oath" the men, though handsome, muscular, and courageous, could care less about the women. Their loyalty is to be sent by their father to live or die for the kingdom, whereas in "the Nightmare" if he could not conquer the kingdom of her, then his life was worse than death. An additional insight is that in both pieces, the women are tormented, left alone. And that's the strangest thing to me. The drama of heroism is in a maiden to be rescued, not abandoned. Thus these pieces demonstrate the very essence of misguided loyalties no matter how noble the intention, and this is the foundation from which all evil is derived. True that.

With the top image first I would say the woman is not only dead
but murdered. The way shes laying down shows almost like
someone killing her. The demon on top shows the evilness
of the death. The horse is also part of it since he was a whitness
and chooses not to do anything. I would say this is a image
of death and evilness.

The second image shows 3 men going against the other man with
the people behind him. The man is holding 3 swords to show peace
and doesnt want war. The people behind him are frightened and
scared. I would say this image is from Rome.

Finally the two pictures are similar because they both show evilness
and death-like. The evil with the first picture are the horse and demon, &
the bottom image is the 3 men representing evil. It also shows innocence;
the woman did nothing wrong as is killed, meanwhile the people in the
second image are innocent and being terrorized.

I tried my best & I hope this helps!

The top image is of a single person, who appears dead and the bottom image contains several people who are performing actions. The top image has some allegorical figures in the background, the horse and what looks like a troll sitting on her chest - the bottom image is attempting to look realistic. The bottom image also has illusion of depth with the arches and implied space behind the arches. The top image is mostly in one plane.

The first painting is The Nightmare, a 1781 oil painting by Anglo-Swiss artist Henry Fuseli (1741–1825). Since its creation, it has remained Fuseli's best-known work. With its first exhibition in 1782 at the Royal Academy of London, the image became famous; an engraved version was widely distributed and the painting was parodied in political satire. Due to its fame, Fuseli painted at least three other versions of the painting.
Interpretation of The Nightmare have varied widely. The canvas seems to portray simultaneously a dreaming woman and the content of her nightmare. The incubus and the horse's head refer to contemporary belief and folklore about nightmares, but have been ascribed more specific meanings by some theorists. Contemporary critics were taken aback by the overt sexuality of the painting, which has since been interpreted by some scholars as anticipating Freudian ideas about the subconscious.

The second is Oath of the Horatii ,a painting by Jacques-Louis David ( 1748-1825) accomplished in 1784, before the French Revolution, which depicts the Roman salute. It grew to be considered as paradigm of neoclassical art. The painting increased David's fame, and allowed him to rear his own students.
The painting illustrates the three sons of Horatius swear on their swords, held by their father, that they will defend Rome to the death. The principal sources for the story behind David's Oath are the first book of Livy which was elaborated by Dionysius in his Roman Antiquities. However, the moment depicted in David's painting is his own invention.

Both paintings are the best known works of each artist .The work of David clearly reflects the contrast among loyalty, bravery, and patriotism versus sorrow and love. Henry Fuseli’s The Nightmare depicts an image of the sublime and terrible. Fuseli created an example of Romantic art. It provides as a stark contrast to David’s example of Neoclassicism. Social factors attributed to the varying styles of these artists. A change to the sublime and intense human emotions became popular and this is exhibited in Fuseli’s work.

Both artists died the same year 1825.

Differences: I don't think the woman in the first painting is dead. I think she is sleeping. The thing on top of her is a sitting demon. The horse with it's dead eyes is the demon's companion. This painting has a lot of dark colors to it, as a matter of fact just about everything but the woman is dark.

Whereas the second picture is lighter and has lighter colors. I don't think the old man is trying to stop the war. I think he is trying to give his three sons swords. I say it is his three sons, because one of them is holding another. The three women behind the older man with the swords are the young man's wives. They are already mourning the loss of their companions.

Similarities: All the women are in a state of stress, by some kind of torture. The woman above, because a demon is sitting on her and won't let her move. The women below because their husbands are going to leave, and they can't stop them.

Another similarity, a horse brought the demon to torture this woman, the young men would most like ride to fight their enemies, as they are wearing colorful clothes (usually means higher status).

In the first image the woman has fainted or passed away, with a demon (gargoyle) and dark horse awaiting her. In the second, we see three Roman men claiming swords from a man who is in front of the women, likely to show that he is being attacked while they watch in a fearful manner. Both images use a dark palette, with red as the strong color of anger, death, and blood. Innocence or truthfulness is being shown by the color white, indicating the angelic nature of the woman, or the idea that the roman soldier is the good soldier, vs the other man in red. Both images represent the idea of war or death, as the soldiers are ready to fight, and the horse in the above image is ready to ride the woman to death.

The top image of the woman is a calm image, while the bottom is focused on movement. In the top image, the demon looks directly at the audience, inviting you to focus on him. In the second, the painting is staged, as an illustration or a theatrical production would be.

Both indicate good vs. evil, or light vs. dark and are set in similar time periods. Also, both images have been painted in an oil/gouache and make historical references to Christian forms, such as Hell's horsemen, demons, the trinity, and the mother Mary, as seen in the second image.

Let me know if you need more help! Art major :)

I am certainly not going to compete with some of the answers here,. There are at least two, if not more that are well thought out and fairly well detailed. All I suggest is that you make a note to also add your own interpretation of the paintings to those that have been previously researched. Remember that an artist may not be conveying only one message in his work and that the meaning of art is open to discussion.

Perhaps the demon has taken her soul as a result of her having lusted after another, thus her dreams of ecstasy have turned into a nightmare.

In the second, perhaps the soldiers are vowing their allegiance to their leader by presenting their swords to him as their wives or ladies worry that such an allegiance is to the death.

wow, I wish I had Mahalo to do my homework when I was in grade school.