Many . . . poems in Rib of Earth have the distinctive feel of the spiritual and the religious, which Thumboo has recently attempted to resurrect, but without the same fervour. The religious bases are on the one hand Hindu and Buddhist, particularly in the evocation of the Hindu concept of maya (illusion) as the ultimate truth, and extends to the more general feeling of the transience of life. The beliefs stem from his heritage and his study of ancient history. On the other hand, Christianity is just as persuasive, coming from his Western and literary education. But all this may be simply illustrative of his youthful writing, where the sentiment in the poem is more expansive than the felt experience, which is not fully realised. 
The preceding passage has been quoted from the late Ee Tiang Hong's Responsibility and Commitment: The Poetry of Edwin Thumboo, ed. Leong Liew Geok (Singapore: Centre for Advanced Studies/Singapore University Press, 1997. It can be ordered from Singapore University Press, 10 Kent Ridge, Singapore 119260 [GPL].