Investing is not a science

I quite agree with what Bogle said about investing, because it involves too many kinds of human behaviors like fear, greed,irrationality and a lot of emotions. Financial market has long been too complicated. No one can easily single out any factor to determine how much influence on the market, especially on the psychological side of investor behaviors. So, until now, there is still no clear evidence to precisely predict the short-term volatility of the market through any scientific methods.