Kant's reasoning appears to be circular. He argues that we must think of ourselves free because we are born under moral laws and then claims that we must be under moral laws because we think of ourselves as free. Kant himself notes this in the Groundwork (Groundwork of the Metaphysics of Morals p.111). While he does attempt to answer this objection here, his remarks in the Critique of Practical Reason are more illuminating. There he argues that freedom is the necessary condition of the moral law's existence, but the moral law is the only condition under which freedom can be known. Freedom would exist regardless of our awareness of the moral law; but only because we do know the moral law are we aware of our freedom. Freedom is thus the ratio essendi of the moral law, but the moral law is the ration cognescendi of freedom (Critique of Practical Reason p.4n). (p.33)
Justice is therefore the aggregate of those conditions under which the will of one person can be conjoined with the will of another in accordance with a universal law of freedom (The Metaphysical Elements of Justice p.34)
In so far as [Kant] thinks that justice, like morality, is not to be justified by material and subjective ends, his [theory of justice] is a deontological theory. Yet in so far as his legal and moral theory are founded on a theory of objective ends, it appears to be teleological. The objective end Kant presents is that condition in which each individual's freedom is in harmony with the freedom of all others. And the reason he gives for seeing this as an objective end is that the only (ultimate) end of creation or existence is man, who is the only being whose causality is teleological or directed to ends, and who is yet unconditioned by nature because he is free (Critique of Teleological Judgement p.99). Indeed man is distinguished by his freedom to choose his own ends or purposes, and for this reason the condition which offers the greatest scope to human self-legislated ends is the objective end that should be sought. This is the real end of nature: to attain that condition in which human ends can flourish. (p.38)
If [Hume and Kant's] theories do in fact stand in irreconcilable conflict, as separate defences of the liberal philosophy, Hayek's restatement of liberalism would have either to embrace one and reject the other, or risk presenting an account of liberalism which rests on inconsistent premises. It is the latter course that Hayek chooses, for he sees no fundamental incompatibility between the views of Hume and Kant as far as their social philosophies are concerned. (p.44)
Hayek's critique of constructivist rationalism, and his account of the evolution of rules of conduct in the theory of spontaneous order, are strikingly Humean in character. His political philosophy is, to a considerable extent, founded in Humean assumptions about the nature of society and the place of justice within it. He sees morality as a social institution composed of rules of conduct which have evolved with the social order and have derived their legitimacy, ultimately, from the fact that they facilitate the co-ordination of human activities and enhance society's prospects of survival. He thus follows Hume in regarding justice as an institution which enables man to cope with his circumstances, and denying that the rules of justice can be discovered by reason. At the same time, however, Hayek appears to reject the idea of such a 'conservative' justification of the liberal order. In attempting to uncover the principles of a liberal order he turns to a Kantian emphasis on the importance of freedom as the master principle of the Great Society. His conception of freedom as 'independence of the arbitrary will of another' is indeed strikingly Kantian, emphasizing as it does that liberty means 'the absence of a particular obstacle - coercion by other men' (The Constitution of Liberty p.19). (p.45)
[Unlike Kant, for Hayek] [t]here are no fixed categories of understanding but only constantly adjusting mechanisms of perception; man's capacity to know is developing as much as his knowledge is growing. (p.50)
Hayek differs from Kant in another important way. He does not draw a distinction between 'appearance' and 'reality' or ask if or how we can know 'things in themselves' (The Sensory Order pp.4-5). (p.50)
One important aspect of his epistemology, however, is particularly Kantian: his account of knowledge as rule-governed. In 'The Primacy of the Abstract' he describes the mind according to 'the system of abstract rules which govern its operation (New Studies p.43) (...) While Kant presents a metaphysical, rather than a physiological account of the rule-guided nature of knowledge, his views closely resemble, and illuminate, Hayek's theory. In the first Critique Kant characterizes the faculty of understanding as a 'faculty of rules' which is always 'investigating appearances, in order to detect some rule in them' (A p.126). More than this, rules are necessary if we are to 'know', for these rules enable us to organize experience: 'without such rules appearances would never yield knowledge of an object corresponding to them' (A p.159, B p.198). Kant's concept of the understanding is much like Hayek's conception of the mind as a system of abstract rules, applied when an object or 'appearance' is encountered, so that these objects may be 'classified' or 'known'. (pp.51-52)
Our rules for establishing true coherences - as against illusory ones - are and must remain indeterminate. Any rules we have must be applied, of course: and, to do this, we may have additional rules for their application. But we cannot go on having specific rules for the application of specific rules for the application of specific rules ad infinitum. At some point we must have "rules" of application (if we can call them that) which we cannot specify, because we must simply dwell in them in a subsidiary way. They are part of our deepest commitments. But for this reason they are not specifiable. (Michael Polanyi and Harry Prosch, Meaning p.61)
That erroneous view [constructivist rationalism] is closely connected with the equally false conception of the human mind as an entity standing outside the cosmos of nature and society, rather than being itself the product of the same process of evolution to which the institutions of society are due. (Law, Legislation and Liberty Vol.1 p.5)
Having concluded in the Sensory Order, and in his essays on the philosophy of mind, that the individual was incapable of distancing himself from the cosmos of nature so as to account fully for its operation, Hayek maintains that it is similarly impossible for man to distance himself sufficiently from the cosmos of society to construct a complete account of its structure. Such an account, he argues, would involve an attempt to produce a complete explanation of how society and its institutions have evolved and will evolve, by people who, at the same time, do not know how they themselves are evolving as the members of those institutions, or know how their explanations may affect the development of those institutions. (p.60)
While rules may thus be defended on the basis of their past and current effectiveness or compatibility with social life or with the community's 'sense of justice', they cannot be defended on the basis of a future end-state which comprises the 'total consequences' of those rules (LLL Vol.2 p.19). (p.65)
From Hayek's anti-constructivist perspective, however, Rawls's enterprise appears misconceived. What Rawls is trying to do is to articulate what cannot be articulated. The assumptions made in this attempt are not only implausible but, in fact, presume the absence of problems whose solution is the product (rather than the pre-condition) of justice. (p.69)
The background of unarticulated rules can never be captured to form the first premiss of a syllogism defining justice. It is not that argument about justice and equity is not possible; rather, the idea of criticizing the justice of the social structure as a whole from the perspective a putative sense of justice elicted from that social structure is mistaken. (p.71)
Institutions of justice do not reflect a shared conception of justice. Rather, they reflect man's epistemological predicament: he is able neither to articulate fully his understanding of right and wrong nor to know enough about his world to be certain about his (and others') judgements. Institutions make up for this lack because they embody rules of conduct which have been tested by experience. What individuals do share (to varying extents) is confidence in the appropriateness of the institutions serving this function. (p.71)
The kind of philosophical undertaking Hayek denies is not that which questions the values implicit in social practices but that which seeks at one and the same time to question all social values (New Studies p.19). Implicit in this attitude is the assumption that the task of political philosphy can never be completed, for criticism will always have a place in society in which values change. That there is no single 'reasonable and workable conception of justice' which philosophers can identify or construct does not thus signify the practical irrelevance of social theory but, rather, explains why it will always be a vital part of polity. (p.73)
It is not enough merely to say that the parties in [Rawls's] OP [=Original Position] know all the relevant and true beliefs concerning human nature and social theory; what is needed if we are to know how we would judge from that perspective is not just the assumption that we know: we need that true social theory before us. Rawls does not offer us any such theory. Indeed he cannot; for it is not possible to present a social theory which is not, to some extent, influenced by the interests and assumptions of the theorist. (p.75)
Any construction of a point of view from which to outline [individual] entitlements would represent not a view of persons in society but the view of the single individual involved in that construction. (p.77)
On this basis Hayek suggests that rules of justice cannot be constructed in the abstract but must be the outcome of the social process. Although the activity of theorizing a part of that process, it is no more than that: a part of the process. There can be no blueprints produced by political theory, and all evaluation of the rules and social processes that dominate society must begin by acknowledging the existing tradition within which all social and moral discourse takes place. (pp.79-80)
The contradiction into which Hayek seems to be locked is one in which he is forced to claim that there can be no social theory that can guide our evaluation of the entire structure of our institutions, while conceding that a considerable social theory, explaining the purpose served by our institutions, is necessary for us to evaluate and alter our rules of conduct. (...) This is an important problem. It makes it hard, if not impossible, for Hayek to make any positive claims about the good society: about the principles which govern its operation or how we might move towards it. His anti-constructivist epistemology suggests that we can never comprehend the workings of society well enough to know what kind of rules would best sustain it. (pp.82-83)
By order we shall throughout describe a state of affairs in which a multiplicity of elements of various kinds are so related to each other that we may learn from our acquaintance with some spatial or temporal part of the whole to form correct expectations concerning the rest, or at least expectations which have a good chance of proving correct. (LLL Vol.1 p.35)
The point is that, while it is easy to protect a particular person or group against the loss which might be caused by an unforseen change, by preventing people from taking notice of the change after it has occurred, this merely shifts the loss onto other shoulders but does not prevent it. (Individualism and Economic Order p.21n)
Herein lies the chief merit of the liberal concern for, and emphasis upon, procedural or formal justice rather than the justice of substantive outcomes, for a concern for procedural justice does not mean indifference to, or unwillingness to consider, the nature of the good for man. The concern for procedures betrays a recognition that it is largely because of the rules of justice, which seek to preserve the freedom to pursue the good, that the good can be discovered. (p.118)
Law in its ideal form might be described as a "once-and-for-all" command that is directed to unknown people and that is abstracted from all particular circumstances of time and place and refers only to such conditions as may occur anywhere and at any time. (...) [A]s we move from commands to laws, the source of the decision on what particular action is to be taken shifts progressively from the issuer of the command or law to the acting person. (The Constitution of Liberty p. 218)
In such an effort towards the development of a body of rules, most of which are accepted by the members of society, there will therefore also exist an 'objective' (in the sense of being inter-personally valid, but not of universal [validity] — because it will be valid only for those other members of the society who accept most of its other rules) test of what is unjust. (LLL Vol.2 p.42)
The mind cannot step outside itself to view its own operation. Since the mind, as he [Hayek] conceives it, is a system of rules embedded in a social structure also constituted by rules of conduct, it is similarly impossible for the mind to step outside society and view its operations from beyond. The difficulty of separating mind from society tells against the possibility of the mind comprehending the operation of the whole. (p.180)
This is, perhaps, the main significance of Hayek's Road to Serfdom - not the cogency of his doctrine, but the fact that it is a doctrine. A plan to resist all planning may be better than its opposite, but it belongs to the same style of politics. And only in a society already deeply infected with Rationalism will the conversion of the traditional resources of resistance to the tyranny of Rationalism into a self-conscious ideology be considered a strengthening of those resources. (Michael Oakeshott, 'Rationalism in Politics' p.21)
What remains disturbingly unclear in all this, however, is the relationship between the conservative elements in Hayek, which deny the power of reason successfully to reconstruct human institutions and reject the possibility of rationally justifying them, and the more rationalist Hayek who regards traditions in a more instrumental manner. (p.189)
[In contrast to utilitarianism] His [Hayek's] defence of the liberal order is based not on the claim that its rules will produce end-states we would choose if we knew what alternatives were available, but on the contention that the rules of the liberal order enable us to adapt to a changing environment which is always creating states of affairs which we can never wholly anticipate, let alone choose. (p.197)