From
Common Stocks and Uncommon Profits:
All types of common stock investors might well keep one basic thought in mind; otherwise the financial community's constant worry about and preoccupation with the danger of downswings in the business cycle will paralyze much worthwhile investment action. This thought is that here in the mid-twentieth century the current phase of the business cycle is but one of at least five powerful forces. All of these forces, either by influencing mass psychology or by direct economic operation, can have an extremely powerful influence on the general level of stock prices.
The other four influences are the trend of interest rates, the over-all governmental attitude toward investment and private enterprise, the long-range trend to more and more inflation, and—possibly most powerful of all—new inventions and techniques as they affect old industries. These forces are seldom all pulling stock prices in the same direction at the same time. Nor is any one of them necessarily going to be of vastly greater importance than any other for long periods of time. So complex and diverse are these influences that the safest course to follow will be the one that at first glance appears to be the most risky. This is to take investment action when matters you know about a specific company appear to warrant such action. Be undeterred by fears or hopes based on conjectures, or conclusions based on surmises.
