 To establish that the inductive step in the version of the evidential argument from evil set out above is sound requires a rather technical argument in inductive logic.  But one can gain an intuitive understanding of the underlying idea in the following way.  Suppose that there is a rightmaking property of which we have no knowledge. If an action of allowing a child to be brutally killed possessed that property, then it might not be wrong to allow that action, depending upon the weightiness of that unknown rightmaking property.  But the existence of unknown rightmaking properties is no more likely, a priori, than of unknown wrongmaking properties.  So let us suppose, then, for this illustration, that there are two morally significant properties of which we humans have no knowledge—a rightmaking property \(R\), and a wrongmaking property \(W\).  Let us suppose, further, that these two properties are equally weighty, since, a priori, there is no reason for supposing that one is more significant than the other.  Finally, let \(A\) be an action of knowingly allowing a child to be brutally killed, and let us suppose that the unknown morally significant rightmaking property \(R\) is weightier than the wrongmaking property of knowingly allowing a child to be brutally killed.  One can then see that there are the following four possibilities: