The Little Book of Common Sense Investing

Index mutual funds are the best way to invest for the long term. Bogle was the founder of Vanguard and a strong advocate for index funds. Using an index fund minimizes costs management costs, capital gains and the costs of "market risk". Actively managed funds may be the market at times. However, if somebody is overperforming, this comes at the expense of somebody else's underperformance. Higher fees come out of this. The more money that is paid in fees, the less is available for the investor. People also tend to invest in "hot areas", which often causes them to go in at the peak, while leaving at the nadir. 

Bogle was not very keen on ETFs. He acknowledges that they can be more tax efficient and beneficial for people that hold them for the long term. However, they also allow for frequent trading that could reduce returns.

Bogle's book presents a sound case for indexing, complete with plenty of quotes from other sources. He is open to people adding some other "fun" areas to their portfolio as long as indexing is the mainstay. 

The questions that are not discussed include what happens if everybody indexes? Is there a level of indexing where the market fails to function? And what happens if the market enters a long-term doldrum?