A recent article in The Wall Street Journal reviews a new book about John Maynard Keynes, best remembered as “an economist who made the case for governments to spend their way out of recessions” but, as an investor, was “a kind of proto-Warren Buffett, a diligent savant who would crunch the numbers…and remain unflustered by the churn of the markets.”

The book’s author, Justyn Walsh, a former investment banker and current chief executive of an asset-management firm, chronicles Keynes’ “extraordinary and vivid life” from precocious student to economic adviser for the British delegation to the Paris Peace Conference after World War I.

The book highlights how not even Keynes could resist the “fevered markets of the Roaring Twenties,” losing 80% of his net worth from buying as the market rose. In the 1930s, Walsh writes, Keynes “switched from market timer to value investor, seeking to profit from swings in the market rather than participating in them.” He argued that attempts to time the market were “impracticable and indeed undesirable”  and that the true investor was focused on “ultimate values” rather than “exchange values.”

The article notes how the book draws a “clear intellectual line from Keynes to Benjamin Graham, the evangelist of value investing, and to Mr. Buffett and his many disciples.” It outlines Keynes’ six key investing principles as follows:

• Focus on the intrinsic value of a stock.
• Ensure a large margin of safety between the price you pay and the intrinsic value.
• Think for yourself and be contrarian if necessary.
• Maintain a steadfast holding of stocks, to limit transaction costs.
• Concentrate your portfolio in a few great companies.
• Have the right temperament, balancing equanimity and patience with decisiveness.

The article concludes by citing a Keynes quote that it says could describe the past year: “It is because particular individuals, fortunate in situation or in abilities, are able to take advantage of uncertainty and ignorance…that great inequalities of wealth come about.”