Deontology is ultimately about doing what is right and therefore behaving morally. This does not necessarily translate to obeying the law as the law might not be right or complete, but rather that we are duty bound to follow a set of correctly formulated rules, whatever the outcome might be. We can use the formula of universal law which is a version of Kant’s ethical idea, called the categorical imperative, to examine the moral validity of an act. Kant would most probably have said that Gekko’s opinion can be deemed as immoral and wrong because it would not pass step 3. If every rational person acted with the attitude that greed is good in order to become as rich as possible, it may be detrimental to the whole system and would not be sustainable.