Laissez-Faire is defined as being an economic doctrine that opposes governmental regulation of or interference in commerce beyond the minimum necessary for a free-enterprise system to operate according to its own economic laws. A true believer in Laissez-Faire capitalism would believe in the separation of economy and state. The place where complete Laissez-Faire capitalism fails, however, is in mankind's own greed and desire for riches. This often results in those who are stronger repressing those who are weaker. One could say this shows evidence of an influence of Darwinism in the formation of Laissez-Faire capitalism. The process of natural selection or "survival of the fittest" can be applied to business to justify immoral and illegal business practices, and this was done in America in the 1800's and early 1900's. In Christianity, however, we bear responsibility to our fellow man and not just ourselves.
Modified Market capitalism, by contrast, controls the human desire for riches and greed through more regulation than the "let alone" philosophy of Laissez-Faire capitalism. By taking into account the fact that those who are stronger will try to oppress those who are weaker, Modified Market capitalism controls the economy and thus, society, with stronger regulation.