Man not only thinks but he thinks _progressively_. The _average horse_ of to-day, for example, is probably no more intelligent than was the average equine of the time of Alexander the Great, whose war horse, Bucephalus, attained historical fame. Yet, intellectually, the _average man_ of to-day is _far_ above the average man of Alexander’s time. “Horse-knowledge” is more or less stationary. Through instinct each generation makes use of the knowledge of its ancestors without any noticeable accretions. But “man-knowledge” is a growing product of progressive thought. Man appropriates all the knowledge of his forbears, and then adds to this a bit of his own. By being able to think progressively, man is enabled to _stand upon the shoulders of his ancestors_ and thus to take advantage of a broader vision. We are now led to the conclusion that man’s supremacy is due not only to his ability to think, but to his power of _progressive_ thought. =4. NECESSITY OF RIGHT THINKING.= In the main, man’s thinking has been for his good, that is, in the long run, it has contributed to his general progress. If this had not been so, long since would he have dropped back to the level of the non-thinking animals. Thinking has been defined as the process of affirming or denying connections. Right thinking is, therefore, a matter of affirming the right connections or denying the wrong connections. To put it differently: right thinking is the process of adjusting the best means to a right end; whereas wrong thinking is a matter of overlooking the best means, or directing improper means to a wrong end. Right thinking involves _proper adjustment_; wrong thinking _improper adjustment_. In the intellectual world as in the physical, _improper adjustment_ means extinction. Illustrations of this: (1) A contractor undertakes to build a skyscraper. In the excavation an old wall is discovered. The thought of the contractor is, “I must make a pot of money out of this job, and since this old wall is in the right spot I will build on it, and thus save me ‘five hundred’.” In the course of ten years, without warning, the building topples over and fifty women and children are killed. The contractor is convicted and sent to prison for life. If the builder had thought the right thought; namely, “I want to put up a building that will stand for generations,” he would have survived the competition of his fellows and entered his long home with success etched upon his soul.