Conscience in Buddhism Conscience is described as being the moral sense in which an individual makes decisions. Do Buddhists believe there is a conscience? If so how is it defined
In Mahayana abhidharma, we speak of the two mental factors that I would think are quiet similar to the "moral conscience" that you allude to. These two might be the same as 'shame' and 'conscience' in MA45. The two are:


Shame (Tib. ngo tsha shes pa)
Embarassement (Tib. khrel yod pa)


Regarding shame, the Compendium of Knowledge says:


  Question: What is shame?
  
  Answer: It is an avoidance of misdeeds on
  account of oneself. It has the function of acting as a support for
  effective restraint from misconduct.


An example of shame is to restrain from stealing even when nobody would have known. It is akin to self-respect.

Regarding embarrassment, the Compendium of Knowledge says:


  Question: What is embarrassment?
  
  Answer: It is an avoidance of
  misdeeds on account of others. It has the function of just that [i.e.,
  acting as a support for effective restraint from misconduct].


An example of embarrassment is to restrain from stealing by thinking "there is a camera", paying heed to what others would think of our negativity, or thinking "what would my teacher think if he knew?".