Sri Aurobindo
Letters of Sri Aurobindo
Fragment ID: 20321
The calm immensities of spirit Space.
The golden plateaus of immortal Fire
The moon-flame oceans of unfallen bliss
“Immensities” was the proper word because it helped to give the whole soul-scape of those worlds – the immensities of space, the plateaus of fire, the oceans of bliss. “Infinities” could just replace it, but now something has to be sacrificed. The only thing I can think of now is
The calm immunity of spirit Space...1
“Immunities” in the plural is much feebler and philosophically abstract – one begins to think of things like “quantities” – naturally 
it suggested itself to me as keeping up the plural sequence but it grated on the sense of spiritual objective reality and I had to reject it at once. The calm immunity was a thing I could at once feel. With immunities the mind has to ask: “Well, what are they?”
1937
1 Owing to the close occurrence of the word “immensities” in another line, “immunity” was here used. At present the original word has been restored in a new context (p.47) and the line comes at the end instead of at the beginning of the sequence:
Still regions of imperishable Light,
All-seeing eagle-peaks of silent Power
And moon-flame oceans of swift fathomless Bliss
And calm immensities of spirit Space.