If every event, mental or physical, has sufficient antecedent causes, then as Aristotle said, there can be no "unmoved mover." But free will is supposed to be just such an unmoved mover, free to do what it chooses, hence an "uncaused mental cause" of our actions. This led the 17th-century philosopher Spinoza, and others since him, to conclude that free will is an illusion.
For the time being I'll presume that Kauffman's summation of Aristotle is accurate on this point, but the use of the phrase "unmoved mover"-- usually employed as a description for a God who creates the universe out of nothing-- confuses the issue as to what would be involved in an "uncaused mental cause."
Following the logic of Kant expressed at the begining of CRITIQUE OF PURE REASON, it should always be a given that even if there is a core of "agency" within a given subject, that subject is always vulnerable to the influences of the contingent world in which he exists. It goes without saying that this "mover" can never be "unmoved."
What I believe Kauffman means to say is that the "free will" expressed by a subject's given choice of his actions is not ENTIRELY caused by contingent factors. This would be the attitude expressed by psuedo-scientists like Mickey Marx (the subject's will to choose is a manifestation of his society) and Ziggy Freud (the subject's will to choose is a manifestation of his familial upbringing). This attempt to reduce the will of the subject to an epiphenomenon spawned by a greater phenomenon would not have been possible until the birth of Western science, which as noted here took on greater cultural significance than ever before once science began to deliver to humankind an increasing control over the physical world.
Kant was as aware as anyone as to the influence of contigent physical factors, but he still believed that free will-- and by extension, the general concept of freedom-- was a factor in its own right, one subsumed by his categorial imperative.
Freedom is independence of the compulsory will of another, and in so far as it tends to exist with the freedom of all according to a universal law, it is the one sole original inborn right belonging to every man in virtue of his humanity.
Kant is problematic for moderns in part because of his rigidity about the nature of his proposed "universal law." Still, Kant emphasizes, as Marx and Freud do not, that it is possible to exercise free will in spite of compulsion. Marx and Freud, being pseudo-scientists, want to presume the primacy of compulsion, in order to promote their theoretical constructs.
One need not speak of being "unmoved," since this is tantamount to an imputation of omnipotence. Kauffman is on surer ground to speak of an "uncaused mental cause," for in this view the subject's exercise of "free will" is an expression of its inner nature. This nature, by Kauffman's own logic, is not something bestowed upon the subject by a creator-god, but is rather a concatenation of all those factors-- causal and acausal-- that have made the subject of an individual, willing creature. One may say that a given choice has been "caused" by the nature of the subject, but it is "uncaused" in the sense of reductive science; i.e., it has not been produced by forces/phenomena outside the subject's compass.
There is a possible objection to Kauffman's philosophy. In REINVENTING THE SACRED he does not manage to show in what way his principal of "quantum coherence"-- proposed as a principle that may have contributed to the formation of the "open thermodynamic systems" of living organisms -- makes the subject's will an "uncaused mental cause." In the view of most reductivists, if quantum-energy factors did influence the formation of life on our planet, those factors would just be another set of contingent influences, as much as the sun's radiation or the presence of oxygen.
Kauffman repeatedly explains his title by saying that humans do not need supernatural forces to explain life any more, but that humans should regard their own "agency" as sacred. He repeats, again and again, that human systems of value are not irrelevant epiphenomena, that they do not lose their meaning simply because all humans are composed of subatomic particles. But Kauffman is not able to say just how a given system of value remains significant. If one society forbids any form of incestual marriage, and another society permits certain forms, surely both of these societies have assigned value to their cultural practices; both are results of "willing" and "agency." By Kant's "universal law," one of these must be right and the other wrong. Kauffman does not say this, and in fact refutes Kant on this point. But he does not solve the knotty problem as to how systems of value can contend with each other, and yet remain individually significant.
For a possible de-knotting, stay tuned for Part 2.
ADDENDUM: The de-knotting actually appears in the discussion of taste and intersubjectivity in KIRBY'S CHOICE PT. 2.