For the Russian philosopher Berdyaev, freedom is absolutely fundamental. And freedom is connected with subjectivity and Spirit, rather than the objective (measurable) external world.
All attempts to locate meaning and value in things outside the human soul are doomed to fail. Thinking of the universe as an organism, for instance, seems like an improvement over thinking of it as a dead mechanism. It turns the cosmos into a living entity with a purpose, but it also means thinking of people as mere cells in this organism to be subordinated to the larger whole. Nationalism turns the nation into a false idol to be worshipped. Neither “history,” nor “progress,” nor “the human race,” nor Platonic Forms are particularly significant or even real. They are hypostatizations and abstractions. For Berdyaev, the concrete individual personality is the full locus of reality and value. Anything else renders the personality a meaningless nothing to be used as a means to some other end.
Kant, who also saw human beings as ends in themselves, pointed out that freedom must be a fundamental aspect of human subjectivity because morality exists.  This is known directly from experience. We know that we are morally responsible for our actions and we have experienced the guilt of failing in our moral duty. Conversely, other people have let us down and behaved unjustly towards us. Morality cannot exist without freedom. We should let the datum of morality determine our theories and speculations about ultimate existence. If morality is possible, and we know it is, then freedom exists.