Ayn Rand (Objectivism):
Freedom, in a political context, means freedom from government
coercion. It does not mean freedom from the landlord, or freedom from
the employer, or freedom from the laws of nature which do not provide
men with automatic prosperity. It means freedom from the coercive
power of the state—and nothing else.
Ludwig von Mises (Human Action Chapter XV Section 6):
Only within the frame of a social system can a meaning be attached to
the term freedom. As a praxeological term, freedom refers to the
sphere within which a acting individual is in a position to choose
between alternative modes of action. A man is free in so far as he is
permitted to choose ends and the means to be used for the attainment
of those ends. A man's freedom is most rigidly restricted by the laws
of nature as well as by the laws of praxeology. He cannot attain ends
which are incompatible with one another. If he chooses to indulge in
gratifications that produce definite effects upon the functioning of
his body or his mind, he must put up with these consequences. It would
be inexpedient to say that man is not free because he cannot enjoy the
pleasures of indulgence in certain drugs without being affected by
their inevitable results, commonly considered as highly undesirable.
While this is admitted by and large by all reasonable people, there is
no such unanimity with regard to the appreciation of the laws of
Also, you can fly provided you have enough money for a plane ticket. You can't float unaided. I don't know of any philosopher who claims you're not free because you can't float unaided.