Defensive Investor or Enterprising Investor?

Graham divides investors into two categories- "defensive Investors" and "enterprising investors" (a less rude term than agressive) and sets out portfolio guidelines for each.

Risk/Reward has always been the traditional divisor between a "defensive" and an "enterprising" investor. Graham disagrees.

Traditionally: Defensive Investor- Low tolerance for risk, therby expecting moderate returns.
  Enterprising Investor- High tolerance for risk, thereby expecting higher returns.

While Graham supports the interpretation that those prepared to take less risk can expect lesser returns, but he does not see this a the major differentiating factor between defensive and enterprising investors.

Graham suggest that it is not risk/reward that seperates the defensive from the enterprising, but the divisor is the AMOUNT OF INTELLIGENT EFFORT that the individual is prepared to apply to selecting their invesments. Therefore:

Defensive Investor - one whom prefers the role of a "passive" investor- someone who wants both saftey and freedom from concern.

Enterprising Investor - one whom exercises maximum intelligence and skill.

Grahams disagreement from the traditional interpretation of "defensive" and "enterprising" is certainly logical, as value shares do not neccesarily carry any higher risk than other forms of investment.
  For example, one of Grahams favourite methods of picking shares was to select companies that were trading on a significant discount to Net Current Asset Value (Essentially where the net current assets the company owns are priced higher than the shares). Although such companies require diligence to find (for the enterprising investor), arguably they carry less risk as they are likely to offer safety of principle, even if the business collapses.