What was St. Thomas Aquinas's view on the difference between punishment accorded to original sin and punishment accorded to individual sin? Many different thinkers in Catholicism have proposed different theories regarding what original sin is compared to individual sin. From this, different theologians have thought that original sin incurs different punishment than individualistic sin. 

I am reading St. Thomas Aquinas and it would seem to me that he believed original sin's punishment is an immediate loss of fullness, where 'human nature is left to itself, and deprived of original justice'. Does this punishment however equate to eternal damnation, or does eternal damnation follow as a consequential punishment to the fallen state of deprived justice? In other words, is the punishment of original sin equatable to death and subsequent orientations to sin and does specific punishment (being possibly eternal damnation, punishment in purgatory, etc) accorded to certain individuals, follow as a possible consequence if not prevented by grace?

Also, Aquinas notes the distinction between satisfactory punishment (punishment of a penitent nature serving the potential of merit) and penal punishment (punishment accorded legally to the individual to fulfill justice). 

Would the punishment for original sin, if the previous suggestion that original sin's punishment is not an eternal damnation but rather only the 'loss of original justice', be of a satisfactory punishment nature (if such were to be possible through grace)? And if such is so, would the individual facing eternal damnation be of a penal punishment nature?
St. Thomas Aquinas was born in 1225 or 1227 and died in 1274. Pope Innocent III (1198-1216) had already defined the dogma:


  "We say that a distinction must be made, that sin is twofold: namely,
  original and actual: original, which is contracted without consent;
  and actual which is committed with consent. Original, therefore, which
  is committed without consent, is remitted without consent through the
  power of the sacrament; but actual, which is contracted with consent,
  is not mitigated in the slightest without consent. . . . The
  punishment of original sin is deprivation of the vision of God, but
  the punishment of actual [mortal] sin is the torments of everlasting
  hell." (DZ 410) - Source: Limbo in Church Doctrine | Question
  from John Harden on 01-01-2008 | EWTN Catholic Q&amp;A.


We should then expect that St. Thomas Aquinas would adhere to this Church dogma and teach it; and he does so in  New Advent: Summa Theologica > Supplement > Question 69. Matters concerning the resurrection, and first of the place where souls are after death > Article 7. Whether so many abodes should be distinguished?


  The abodes of souls are distinguished according to the souls' various
  states. Now the soul united to a mortal body is in the state of
  meriting, while the soul separated from the body is in the state of
  receiving good or evil for its merits; so that after death it is
  either in the state of receiving its final reward, or in the state of
  being hindered from receiving it. If it is in the state of receiving
  its final retribution, this happens in two ways: either in the respect
  of good, and then it is paradise; or in respect of evil, and thus as
  regards actual sin it is hell, and as regards original sin it is the
  limbo of children. On the other hand, if it be in the state where it
  is hindered from receiving its final reward, this is either on account
  of a defect of the person, and thus we have purgatory where souls are
  detained from receiving their reward at once on account of the sins
  they have committed, or else it is on account of a defect of nature,
  and thus we have the limbo of the Fathers, where the Fathers were
  detained from obtaining glory on account of the guilt of human nature
  which could not yet be expiated.


Summary: According to St. Thomas [in line with Church Teaching], the punishment of those dying in actual [mortal] sin and those dying only in original sin is eternal hell, though punished with different penalties and in different places. The former going to hell proper and the latter to limbo of children.



Further Reading: The Four Sections of Hell (St Thomas Aquinas) by Dr Taylor Marshall.