"The Purusha Sukta is a theory of the origin of the Universe. In other words, it is a cosmogony. No nation which has reached an advanced degree of thought has failed to develop some sort of cosmogony"./1

"Cosmogonies have never been more than matters of academic interest and have served no other purpose than to satisfy the curiosity of the student and to help to amuse children."/2

"This may be true of some parts of the Purusha Sukta. But it certainly cannot be true of the whole of it. That is because all verse of the Purusha Sukta are not of the same
importance and do not have the same significance. Verses 11 & 12 fall in 1
category"/3

"& the rest of the verses fall in another category. Verses other than II and 12 may be regarded as of academic interest. Nobody relies upon them. No Hindu even remembers them. But it is
quite different with regard to verses 11 and 12."/4

”Prima facie these verses do no
more than explain how the four classes, namely. (1) Brahmins or priests, (2) Kshatriyas or soldiers, (3) Vaishyas or traders, and (4) Shudras or menials, arose from the body of the Creator”./5

"But the fact is that these verses are not understood as being merely explanatory of a cosmic phenomenon. It would be a
grave mistake to suppose that they were regarded by the Indo-Aryans as an innocent piece of a poet's idle imagination."/6

"They are treated as containing a
mandatory injunction from the Creator to the effect that Society must be constituted on the basis of four classes mentioned in the Sukta.Such a construction of the verses in question may not be warranted by their language"/7

"But there is no doubt that according to tradition this is how the verses are construed, and it would indeed be difficult to say that this traditional construction is not in consonance with the intention of the author of the Sukta."/8

"Verses II and 12 of the Purusha Sukta are, therefore, not a mere cosmogony. They contain a divine injunction prescribing a particular form of the constitution of
society."/9

An interesting extract from "Who were the Shudras" by B R Ambedkar.