Aldo Rossi | Illustration

Aldo Rossi | Teatro del Mondo

Le Corbusier :
"He argued that by following the Engineer's Aesthetic the architect could achieve a platonic grandeur that would resonate on a sounding-board possessed by everyone. This was inspired by the law economy of economy and governed mathematical calculation based on the universal aesthetic of the machine age."

The Idealist view was derived from Plato, and its interpretation continues to exercise philosophers.

It's easier to describe it's impact on architecture, by arguing that all object in the physical realm are imperfect variations of ideal versions that exist in the realm of ideas Plato gave rise to traditional representation of the ideal form.  (Look up Utopia)

Sir Christopher Wren on Idealism:
"There are two causes of beauty - natural and customary. Natural is from geometry consisiting in uniformity, that is equaliy and proportion. Customary beauty is begotten by the use, as familiarity breeds a love for things not in themselves lovely. Here lies the great occasion of errors, but always the true test is natural or germetrical beauty. Geometrical figures are naturally more beauful than irregular ones : the square, the circle are the most beautiful, next to the parallelogram and the oval. There are only two beautiful positions of straight lines, perpendicular and horizontal; this is the form of nature and consequently necessity, no other than upright being firm  "

Emphasis :
Form, Proportion, Symmetry. 
influencing works of architects such :  Leon Battista Alberti and Andrea Palladio.

Villa Capra "La Rotonda"

Santa Maria Novella

Winckelmann on Ideal Forms :
"He rejected the sensual nature of art and advocated an idealized expressionless beauty based on pure form, free of secondary elements such as color and texture - Le Corbusier 'Law of Rippon' (A French whitewash) as means of revealing the formal qualities of architecture"


Read more - "The Mathematics of the ideal villa , by Colin Rowe"
Wheres he compared Le Corbusier early work with Palladio.


Forms Free of Imperfection. 
- 100 Ideas that Changed Architecture Book by Richard Weston

References :
Public Domain, https://commons.wikimedia.org/w/index.php?curid=5315960
100 Ideas that Changed Architecture: Richard Weston - Amazon.com
https://amzn.to/3opHEeM
By No machine-readable author provided. JoJan assumed (based on copyright claims). - No machine-readable source provided. Own work assumed (based on copyright claims)., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=409060

Get the Book on Amazon : 

1_Piero della Francesca - Flagellation of Christ (c.1455-60) Showcasing a Pictorial space using perspective.

Buildings built around the proportions of the human figure. 

Mid-fifteenth century

• - General curriculum (studia humanitatis)
• - New world view  
• 
  

2 _ 16th century portrait of Giovanni Pico della Mirandola.

3_10 Books of Architecture by Vitruvius

4_Leonardo Da Vinci's Vitruvian man

5_Classical order of Classical Greek and Roman architecture (Columns)

References : 
--100 Ideas that Changed Architecture by Richard Weston:
Image 1 : Public Domain, https://en.wikipedia.org/w/index.php?curid=2030007 Image 2 : By Italian School, Anonymous - WestminsterCollege.edu, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6676044 Imge Image 4 : https://www.emaze.com/@ALIFRLZR/Leonardo-Da-Vinci