Necessity of evil. Proof by contradiction

pdf2  download / print this text

From Augustin to modern thinkers Christian tradition has perceived evil as an unavoidable by-product of our free will. Possessing the free will we can choose either evil or good while taking our moral decisions. Evil is the cost here but without freedom of choice there would not be good either. Since right and wrong moral acts can exist only when freedom exists.
So evil is necessary, inevitable, and certain.

The problem is that this thesis could be simply rejected as it can be argued that there is no logical contradiction in the existence of beings who would act freely and always go right. That means that God could create free humans choosing good. This is how John L. Mackie reasoned:

“if God has made men such that in their free always choices they sometimes prefer what is good and sometimes what is evil, why could he not have made men such that they always freely choose good? If there is no logical impossibility in a man’s freely choosing the good on one, or on several, occasions, there cannot be a logical impossibility in his freely choosing the good on every occasion. God was not, then, faces with a choice between making innocent automata and making beings who, in acting freely, would sometimes go wrong: there was open to him the obviously better possibility of making beings would act freely but always go right” 1

Alvin Plantinga rejected this Mackie’s thesis using the concept of trans-world depravity set in the logic of possible worlds. Mackie in response strongly criticised Plantinga’s concept of trans-world depravity. Instead of scrutinizing Plantinga – Mackie blows exchange (inconclusive in my opinion), I would like to settle the dispute with a simple proof that free will really and inevitably results in existence of evil. And therefore, Plantinga is right.

That evil is indeed necessary can be shown by the proof by contradiction. It establishes the truth of a proposition by showing that its antithesis would imply a contradiction. In our case, antithesis that runs: “a world of free persons always going right can exist” must be assumed as true. Next, one should ponder over its consequences. Does it not lead to contradiction? And more precisely, does “going always right” not contradict our assumption about free will? If so, our thesis that existence of evil in a free will world is necessary will be defended.

Therefore we have the following set of sentences:

1. thesis to be proved: in a world of freedom evil is unavoidable, necessary

2. premise: free will exists

3. the antithesis: evil is not necessary because “there is no logical impossibility in man’s /…/ freely choosing the good on every occasion”

Therefore, let us start our proof.

At first, let us assume that it is true that a world of free persons always doing good is possible. The question arises what conditions should be met for such a world to exist. The first fundamental condition is that free persons always doing good cannot differ in their assessment what is good and what is evil. If they differed on it they would choose good assessed by the others as evil.

But we are not talking about such a world, because such a world exists already. We are looking for a better one where everybody is not only convinced that he does good but does not deny that the others do good as well. He knows that since his life experience and everyday observations of the others confirm that assessment.

Therefore, the first prerequisite for all choosing always good, is the same way all of us assess all acts, events, expressed opinions and intentions as good or bad.

In the real world however, people differ in Their assessment whether a given act is good or bad. There are several reasons for that. I assess but do not know all circumstances and if I knew them all, my assessment would probably be different. I assess differently than my companion, because I regard it as bad while he considers it as good. I assess something the way I do because my emotions just blind me and when they extinguish, I may change my mind. We assess differently others’ decisions because of our divergent interests. I assess a given act differently than my neighbor because I know from the experience I have, and he does not, what results might be expected. What’s more, different appraisals result from our different views on economic, political and social issues. Our different views on ethics and religion also influence our assessment. Whether a given act will be assessed positively or negatively is also the result of our personality, e.g. whether we see the world around us through rose-coloured spectacles or paint it as a gloomy picture. Having wads of money changes our vision as well.

I could prolong the list of factors diversifying our assessments and color it with many tasty examples. But instead I want to focus on one issue only: what should be done for all of us to assess every deed the same way as good or bad.

It is hard to imagine it, looking at the real people in the real world. There is no chance that Joanne Rowling, Wladimir Putin, Lionel Messi, Pope Francis, Fidel Castro, Emperor Akihito and the whole rest of the world would suddenly agree on everything. But let us think, purely hypothetically, about the restart of the Universe. God has a free hand again. What conditions must be met for all to assess everything the same way?

A list is probably a long one but among the most important conditions is the same or at least much the same hierarchy of accepted values of all people. Then indeed, we all would perceive the acts and intentions, both ours and the others’, exactly the same way. But the same or much the same hierarchy of values should not be understood as all divergences’ killer. For example, lack of the same body of knowledge may diversify our positions regardless of the same hierarchy of values. So, common hierarchy does not eliminate differences and discussions, but is the basis of deep, (so to speak) pre-established axiological consensus which ignites not a confrontation but discussion with common thinking over the problem, kind of minds fusion to face the issue together. And it always leads to reaching the view agreed and accepted by all. The identical hierarchy of values is not an abstract concept although its examples relate to small groups only. Let us think of the circle of close friends or members of secret combat groups. Good examples are also elite goal-oriented organizations based on clear axiological foundations and meticulous selection. Like Opus Dei. But in all these cases the same, joint hierarchy of values relates to a very limited number of persons. Quite often such a community is directed against others. Whereas Mackie says such a possibility is logically available to all beings having free will.

The fundamental question arises here. How can God give to all the freedom to choose between good and bad, and therefore freedom to assess what is good and bad, but simultaneously impose upon all the same hierarchy of values which in fact determines the assessments what is good and bad, what is smaller and bigger good and what is smaller and bigger bad. It is my firm belief that we encounter a contradiction here because imposing such a hierarchy upon all of us is contradictory to our freedom to choose as this freedom encompasses not only choosing good or bad but also freedom to choose what should be judged as good or bad.

The idea of free persons always going right turns out to be self-contradictory. Choosing always good requires firstly identical assessment of what is good and bad and that in turn requires, before any assessments are made, the same hierarchy of values which determines our later choices. Therefore, freedom to choose to do always good requires the elimination of free choice of hierarchy of values. But the freedom of moral choices with the amputated freedom to choose hierarchy of values is not really a freedom of choice. Therefore, thesis about freedom always choosing good is self-contradictory.

Pointing out the contradiction between the premises and the thesis opposite to the one being proved leads to the recognition of the latter as true. In our case there is self-contradiction between the premise about free will and the thesis that evil is not necessary as the world of free people always going right is logically possible. In consequence, the thesis of unavoidability of evil in a world of free will is true.

The proof I have given can be depressing. Evil is necessary and inevitable in our world. This is sad. But my goal has been quite opposite. The proof I have provided is to defend and supplement what Alvin Plantinga shows in his book “God, Freedom, and Evil” – that belief in God is rational, non-contradictory and compatible with our knowledge of the world. Its only weak point was polemics with Mackie. I believe that now, with my addition, Plantinga’s proof is complete.


  1. John L. Mackie, Evil and Omnipotence, in: Mind, New Series, Vol. 64, No. 254, April 1955, str. 209