It's nonsensical to derive a price/earnings ratio by dividing the known current price by unknown future earnings.
Benjamin GrahamThe 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.
Benjamin GrahamNo statement is more true and better applicable to Wall Street than the famous warning of Santayana: "Those who do not remember the past are condemned to repeat it".
Benjamin GrahamThe thing that I have been emphasizing in my own work for the last few years has been the group approach. To try to buy groups of stocks that meet some simple criterion for being undervalued-regardless of the industry and with very little attention to the individual company.
Benjamin GrahamThe art of investment has one characteristic that is not generally appreciated. A creditable, if unspectacular, result can be achieved by the lay investor with a minimum of effort and capability; but to improve this easily attainable standard requires much application and more than a trace of wisdom. If you merely try to bring just a little extra knowledge and cleverness to bear upon your investment program, instead of realizing a little better than normal results, you may well find that you have done worse.
Benjamin Graham