message of the movie
From what I have read about this movie over the years,it's meaning has to do with the the uncertainty of man's place in creation/the universe in the wake of the revolutionary scientific and technological advances that had taken place in the years from the end of WW II to the movie's creation.
For centuries man was believed to hold a unique place in creation/the universe.
Unprecedented break throughs in physics(A-Bomb,H-Bomb,gamma radiation,space exploration(rockets,carting deep space,genetics(Watson & Crick and DNA)-to name a few- all functioned to shed new light on the physical world and the order and importance of all things in it,including man.
Shrinking is a metaphor for science impuning the exhalted stature of pre mid 20th century man.
No devine love child,no fallen angel,no paradise lost,no nothing! Just a mass of protoplasm governed by the laws of the physical world.As far as the universe was concerned the spider,the cat and Scott Carey were all equal.