It's nonsensical to derive a price/earnings ratio by dividing the known current price by unknown future earnings.

Most of the time common stocks are subject to irrational and excessive price fluctuations in both directions as the consequence of the ingrained tendency of most people to speculate or gamble... to give way to hope, fear and greed.

... the loss of public confidence in the financial community growing out of its own conduct in recent years. I insist that more damage has been done to stock values and to the future of equities from inside Wall Street than from outside Wall Street.

The individual investor should act consistently as an investor and not as a speculator. This means ... that he should be able to justify every purchase he makes and each price he pays by impersonal, objective reasoning that satisfies him that he is getting more than his money's worth for his purchase.

We have not known a single person who has consistently or lastingly make money by thus "following the market". We do not hesitate to declare this approach is as fallacious as it is popular.

we have complaints that institutional dominance of the stock market has put 'the small investor at a disadvantage because he can't compete with the trust companies' huge resources, etc. The facts are quite the opposite. It may be that the institutions are better equipped than the individual to speculate in the market.But I am convinced that an individual investor with sound principles, and soundly advised, can do distinctly better over the long pull than large institutions.

The most striking thing about Graham's discussion of how to allocate your assets between stocks and bonds is that he never mentions the word "age".