few of us are altogether innocent

However, if giving up revenge and resentment were sufficient to yield forgiveness, then one could forgive simply by forgetting, or through counseling, or by taking the latest version of the nepenthepill.  But none of those really seems to qualify as forgiveness properly speaking, however valuable they may be in their own right as a means of getting over anger.  The reason is that forgiveness is neither just a therapeutic technique nor simply self-regarding in its motivation; it is fundamentally a moral relation between self and other.

 

Source: http://opinionator.blogs.nytimes.com/2010/12/26/on-forgiveness/