This intelligence-testing business reminds me of the way they used to weigh hogs in Texas. They would get a long plank, put it over a cross-bar, and somehow tie the hog on one end of the plank. They'd search all around till they found a stone that would balance the weight of the hog and they'd put that on the other end of the plank. Then they'd guess the weight of the stone.

The most important factor in the training of good mental habits consists in acquiring the attitude of suspended conclusion, and in mastering the various methods of searching for new materials to corroborate or to refute the first suggestions that occur. To maintain the state of doubt and to carry on systematic and protracted inquiry — these are the essentials of thinking.