When the serpent beguiled Eve in the garden of Eden, it was very reasonable, easily showing that God's restriction of eating from the tree of knowledge was not reasonable.
When Hitler beguiled the intelligentsia of Britain and the US, he was so reasonable that every reasonable person had to admit that he was a tremendous force for good and could not possibly have evil intentions!
Today, it is interesting to observe how reasonableness parades around dressed, as usual, in its robes of self-righteousness, glaring with condescension at the unreasonable rabble. This attitude ultimates in self-destruction because it is all wrong!
So what is the problem with reasonableness? It is self-conscious instead of God-conscious. For example:
1. It makes sense to me - but what of divine Principle, Mind?
2. It feels right - but what of divine Principle, Love?
Operating outside the context of the laws of the universe, inside the myopic personal view, we have only our clever intellect with which to deceive ourselves and others. This explains why the most highly intelligent can be most lacking in good judgement.
There is no escaping "the great I AM, the all-knowing, all-seeing, all-acting, all-wise, all-loving." (S&H) Without this premise, reason is built upon sand. This is not religious belief. It is Science.