Question: The soul is marginal, i.e. it can be on the material or spiritual platforms. Then again, it is stated that the soul is either eternally liberated (nitya-siddhas) or eternally conditioned (nitya-baddha). Don’t these two statements seem contradictory?
Answer by Romapada Swami: The term nitya siddha means those great devotees who are eternally manifesting perfected existence in the spiritual world or although sometimes appearing in this world amongst us for some purpose of serving the Supreme Lord, are actually never contaminated by the material nature at any point of time. The term nitya baddha refers to those who have been conditioned since time immemorial within the material world.
These two terms do not conflict with the two alternative positions for the soul, mentioned in the first part of your question. The grammar of the initial definition of the soul as marginal, however, as found in your question, needs to be modified:
“The soul is called tatastha, or marginal, because although it is spiritual in nature, due to its tiny existence, it can be influenced by either the internal (spiritual) or the external (material) energy of the Lord.”
There is actually no contradiction in these two definitions.