Final answer:
John Stuart Mill's two downsides of freedom include the potential harm to others if freedom is unrestricted and the necessity of limited government intervention to ensure greater happiness for the majority.
Step-by-step explanation:
The two downsides of freedom for John Stuart Mill pertain to the potential harm unrestricted freedom can cause to others and the paradox that some degree of control is necessary to ensure the greater happiness and freedom of the many. Mill's harm principle suggests that while individual liberty is crucial, it must be curtailed if it inflicts harm upon others. Furthermore, Mill recognized the need for government intervention in some circumstances, such as to improve the lives of the working class or to enforce regulations that safeguard the general populace, even though this might restrict the freedoms of certain individuals like middle-class business owners.