Investments are most intelligent when they are most businesslike.
It is amazing to see how many capable businessmen try to operate with complete disregard of all the sound principles through which they have gained success in their own business. Yet every corporate security may best be viewed, in the first instance, as an ownership interest in, or a claim against, a specific business enterprise. For the investor this rule should determine the conditions under which he will permit someone else to decide what is done with his money. In particular, keep away from ventures in which you have little to gain and much to lose. For the enterprising investor this means that his operations for profit should be based not on an optimism but on arithmetic.