Investing in a Down Market

Following is a link from Dave Ramsey's website for a report on investing in a downmarket http://a1611.g.akamai.net/f/1611/26338/9h/dramsey.download.akamai.com/23572/html/dspWiseInvestors.html?ictid=sptlt. I know it is difficult to continue to invest when investments keep going down but they more than likely will be coming up again. Its just a matter of waiting.