Avoiding a "softening of the brain"

In his book, Orthodoxy, G.K. Chesterton has a quote that I thought worth sharing, "Thinking in isolation and with pride ends in being an idiot.  Every man who will not have a softening of the heart must at last have a softening of the brain."  (p. 34)  At that point he was referring to the willingness of Nietzsche, and countless others like him since, to doubt everything.  Yet those who doubt everything in the end doubt themselves.  On what basis can you doubt everything?  There must be some standard, some truth, that is beyond doubt or all expressions of doubt become meaningless.  "By rebelling against everything he has lost his right to rebel against anything." (p. 34)  In the same way, those who say that all paths are true are equally stuck in a quagmire.  If every path is equally valid, how can any choice be made?  If no outcome is more desirable than any other, what is the point of choosing at all?  Thus the rebel who rejects everything, and the man of tolerance who accepts everything find themselves sitting at the same crossroad.  Chesterton pictured Nietzsche and Tolstoy sitting there together, our world today isn't short of others willing to join them.  "They stand at the crossroads, and one hates all the roads and the other likes all the roads.  The result is - well, some things are not hard to calculate.  They stand at the crossroads." (p. 34-35)
It is amazing that in 1908 Chesterton clearly saw that these two forces in philosophy/morality/government were on a collision course that would leave both without anything meaningful left to say.  In the last hundred years his prediction has certainly proven true.  Today our world is convulsed by rebels who hate everything and everyone and idealists who profess to love everything and everyone.  In the end neither of them is leaving that crossroad.