TL;DR

Impressionism was a break from a stagnant past. It made art vibrant, immediate and joyfully of its own time. It taught people to appreciate the beauty in the world around them. However, it also prioritized surface sensation over deeper meaning and avoided the grit of the world it depicted.

The Bad

When Impressionism first emerged, it was met with widespread derision, mockery and even anger from the art establishment, critics and the public. To a 19th-century Parisian, Impressionism was bad because it was seen as technically incompetent, garishly colored, poorly composed and thematically trivial.

Technical "Sloppiness" and Lack of Finish:

The art world of 19th-century Paris was governed by strict rules, enforced by the powerful Académie des Beaux-Arts. A "good" painting was one with a smooth, polished surface, invisible brushstrokes and a high level of detail and finish. Impressionism violated all of this.

• Visible Brushstrokes: Critics saw their quick, broken brushwork as messy, hasty and incompetent. It looked unfinished, like a sketch, not a proper painting.
• Lack of Detail: Figures were often blurred; landscapes were suggestions rather than precise renderings. To the contemporary eye, this looked lazy and unskilled.

"Unnatural" and "Garish" Colors:

The Impressionists' color theory was revolutionary and shocking.

• Rejection of Browns and Grays: They abandoned the traditional muted palette, instead using pure, bright colors directly from the tube.
• Painting Shadows: To paint shadows in blue, purple or green, instead of black or gray, was considered absurd and a failure to represent reality.

Violation of Traditional Composition:

Influenced by photography and Japanese prints, the Impressionists often used cropped compositions that seemed accidental and informal.

• Lack of a Clear Focal Point: Figures might be cut off by the edge of the canvas, as with Degas's ballet dancers. This broke the classical rules of balanced, centered composition.
• Asymmetry and Casual Scenes: Subjects often appeared caught off-guard, which looked undignified and poorly planned.

"Frivolous" and Insignificant Subject Matter:

The Académie valued paintings with historical, religious or mythological themes — art that told a grand story and conveyed a moral lesson.

• Modern Life: The Impressionists painted middle-class people at leisure, ballet dancers, boating parties and landscapes. Critics saw this as trivial, bourgeois and utterly lacking in intellectual or moral weight. It was "art for art's sake," which to them meant art for no purpose.

Perceived Lack of Skill and Draftsmanship:

Because their work didn't showcase the polished, linear precision of Academic artists like Jean-Léon Gérôme, they were dismissed as untrained amateurs who couldn't draw properly. The focus on capturing a fleeting "impression" was seen as an excuse for a lack of technical mastery.

Critique from a modern perspective:

Lack of Emotional or Psychological Depth:

The Impressionist goal was to capture a fleeting moment of light and atmosphere. In doing so, they often avoided deeper narrative, emotion or psychological introspection. The figures in a Renoir picnic or a Monet garden are often types, not individuals with inner lives. Compared to the raw emotion of a Van Gogh or the symbolic depth of a Gauguin (who were Post-Impressionists reacting against these limitations), Impressionism can be superficial.

Avoidance of the "Dark Side" of Modernity:

They painted the pleasant, leisure-filled aspects of modern Parisian life — cafés, boulevards, boating. Meanwhile, the same era was defined by the grim realities of the Industrial Revolution: poverty, social upheaval and the brutal Franco-Prussian War. With a few exceptions (like Manet's later work), they largely ignored this darker, more complex reality, creating a sanitized view of their time.

A Potential Dead End:

The movement's intense focus on optical realism (how the eye truly sees light) pushed painting in a specific direction that could only go so far. The next generation of artists (Post-Impressionists) felt that Impressionism had sacrificed too much — structure, form and lasting ideas — for this transient effect. Artists like Cézanne sought to put the "architecture" back into painting, moving away from pure visual sensation.

Commodification of Beauty:

Today, the overwhelming popularity of Impressionism can sometimes reduce it to a kind of visual comfort food. Their images are reproduced on everything from mugs to calendars, which can make it difficult to see the radical and revolutionary nature they once possessed. The beauty is so immediate that it risks being uncomplicated or decorative.

The Good

It was revolutionary split that was ultimately good for art.

Liberation of Color:

The Impressionists changed how color is used in painting.

• Shadows Have Color: They rejected the notion that shadows were black, brown or gray. By painting shadows with complementary colors (e.g., blue or purple shadows on a sunlit yellow field), they created a vibrancy and luminosity that more accurately mimicked natural light.
• Optical Mixing: Instead of mixing colors on the palette, they placed small strokes of pure, bright color side-by-side. The viewer's eye mixes them from a distance, creating a more brilliant and shimmering effect (e.g., dots of blue and yellow that the eye sees as green).

Celebration of Modern Life:

They were the first major movement to wholeheartedly embrace and paint the world as it was in their own time.

• The "Here and Now": Their subjects were not gods or heroes, but the birth of the modern middle class: people enjoying leisure time at cafés, ballet performances, picnics and new train stations. They captured the energy and transformation of Paris under Baron Haussmann's renovations.
• Democratization of Subject Matter: They asserted that a beautiful painting could be made of a haystack, a water lily pond or a bunch of asparagus. They found beauty in the ordinary.

The Capture of the Fleeting Moment ("Impression"):

• En Plein Air: Painting outdoors (instead of solely in a studio) allowed them to directly observe and record the immediate effects of light, weather and atmosphere. A painting wasn't just of a cathedral, but of Rouen Cathedral at 3 PM in the late afternoon sun.
• A Sense of Transience: Their work is filled with a sense of life's fleeting beauty — the dappled light that will shift in a minute, the train about to release its steam, the dancer who will move from her pose.

Redefinition of Technique and Composition:

• Energetic Brushwork: Their rapid, broken brushstrokes were not a sign of sloppiness but a deliberate technique to convey movement, light and the texture of the scene. It gave the painting a sense of vitality and immediacy.
• "Snapshot" Compositions: Influenced by photography and Japanese prints, they used unconventional angles and cropped forms, making their scenes feel spontaneous, candid and alive, as if the viewer had just glanced at the scene.

The Act of Artistic Independence:

Perhaps their greatest contribution was their rebellion against the system.

• Challenging the Academy: By rejecting the Salon's authority and eventually holding their own independent exhibitions, the Impressionists paved the way for the modern artist as an independent entrepreneur, free to pursue a vision without needing official approval.
• Art for Art's Sake: They championed the idea that a painting's primary purpose did not have to be the presentation of a moral or historical story. Its value could lie in its exploration of color, light and form — a pure visual pleasure.

And Impressionism is still considered good today:

The Gateway to Modern Art:

Impressionism was the essential bridge between the realistic art of the 19th century and the radical, abstract art of the 20th century. By loosening the grip of realism, emphasizing the artist's subjective perception and liberating color, they directly inspired the Post-Impressionists (Van Gogh, Gauguin, Cézanne), who then pushed art even further toward Fauvism, Cubism and Abstraction.

Universal and Accessible Appeal:

While their initial subject matter was modern Paris, their true subject was universal: light, nature and the joy of the moment. This emotional and sensory appeal is timeless and transcends culture and historical context. People instinctively respond to the beauty and optimism in a Monet water lily painting or a Renoir dance scene.

A Testament to Perception:

Impressionism teaches us to see differently. It reminds us that what we perceive is not a static, detailed photograph, but a shimmering, ever-changing interplay of light and color. It is an art that celebrates the very act of seeing.