It’s very comforting to propose moral hierarchies where everyone is at the same time mostly good, but with an unavoidable bit of evilness which does not make him really bad, just a little more human. Therefore, everyone has a moral battle inside himself, permanently undecided, but also undecidable, a struggle bound by it’s very essence to have no end.
It’s an easy and comforting idea, but it’s completely stupid. Believing it does make our lives worse.
First of all, in it’s basic form, that is, in it’s obvious and “common-sense”™ reading, the theory is just a poor excuse for everyone act immorally whenever it suits him, and still pretend to be able to pass moral judgement over everyone else.
Even if one acts towards his own selfish interests, towards a biased “greater good”, or based in rabid dogmas, he still can say he was being, mostly, just a good, normal person, and that whatever horrible things he just made were just momentary (and forgiveable) lapses.
But, besides presenting a dangerous loophole on morality, this idea of a mixed nature of man is also a philosophical crime. It is very, very poor logic gaining a honored seat at the table of general ethics.
The idea is one which cannot be verified, cannot be proved wrong or right, cannot be checked or contextualized. It is just impossible to “open” the “nature”™ of “man” and see if it is good or bad. And this means that this idea (that man is part good and part bad) will remain a untouchable dogma if we choose to believe in it. Also, the only thing that sustains the idea is this very choice.
Also, it is a devious hideout for dangerous assumptions. Like, for example “what is good”, “what is the source of goodness”, and “why are we here, after all” — all ideas which one cannot be directly and certainly connected with the basic idea we are criticizing, but nevertheless are connotatively reinforced by it.
As a concept, it is very poor because it is, but at the same time not quite, and, therefore, we cannot use the idea in any fruitful line of thought.
It also leads to the dilemma of whether man is basically bad with some goodness which must be taken care of, or basically good with some badness which must be fought. Those two ideas (that are, completely and fundamentally unverifiable) have been used as bases for readings of the world and of society that have very real impasses at their hearts — and therefore avoid the progress of understanding.
But the real crime of this mixed-good-and-evil idea of man is that it puts the crucial point of every moral judgement in an inaccessible place! By proposing that every human being has the very Goodness™ (and Badness™ also) in it’s nature, in the core of it’s own being, we are also proposing that all moral judgement is a direct comparison.
In other words, that when one says something to be good or evil, one is not making a consideration (as subject to error and imprecision as “the day is hot” or “i prefer the yellow one”), but actually one is measuring the real essence of the object.
To explain further: the idea that man has in it’s essence some good and some evil makes our (very subjective) likes and dislikes more important than our thought or our long-term plans.