Apologies for the delay in responding, John, I’ve been on vacation.
You ask whether Kant could be considered a classical liberal. I think the answer must be – yes, in some respects, no, in others.
If you’re looking for a succinct account of his thought vis-a-vis rights and liberty, I can recommend David Gordon’s lecture. You can find Dr Gordon’s lecture at: https://www.youtube.com/watch?v=BOMFS7PcrAU
I didn’t include any podcast/recording on Kant in the LibertyClassroom lectures but when I produced my book, Freedom’s Progress?, my conscience pricked me and I wrote a chapter on Kant for that work.
It must be said that although there’s much that a lover of political liberty can take from Kant’s work, it would be going much too far to portray him as advocating an embryonic form of libertarianism. ‘The libertarian tendency to appeal to both Locke and Kant in support of their arguments betrays a tendency to conflate Locke’s natural right to freedom with Kant’s innate right to freedom,’ writes Katrin Flikschuh. She continues, ‘It is important to distinguish between them. While libertarians are often criticised for departing from question-begging premises, Kant’s conception of innate right to freedom as a right that individuals possess “merely in virtue of their humanity” is grounded in his metaphysics of freedom as a (shared) idea of reason. Whether or not one finds Kant’s account defensible is a separate question—the point is that, given his metaphysical presuppositions, Kant is an unlikely proponent of a libertarian conception of individual freedom as a natural right.’ [Flikschuh, 123-124, n. 25]
On the plus side, this is what of wrote of Kant as a lover of liberty: “In the ‘Introduction’ to the ‘Doctrine of Right’ Kant makes a ringing claim that should warm the heart of every lover of liberty: ‘Freedom,’ he says, (and by ‘freedom’ here he has in mind not some transcendental or noumenal account of freedom but simply the condition of being unconstrained by another’s choice) ‘insofar as it can coexist with the freedom of every other in accordance with a universal law, is the only original right belonging to every man by virtue of his humanity.’ [Kant 1797, 30] Kant draws a distinction between what we might call negative freedom, the freedom to act without external constraint, and positive freedom, which is the ability of the will to be a law unto itself. Negative freedom is a necessary but not a sufficient condition of positive freedom.
“In his ‘On the Relation of Theory to Practice in the Right of a State,’ Kant denies not only that the welfare of its citizens can provide the basis of state power but he also rejects the idea that the state can legitimately legislate for a specific concept of happiness for its citizens. ‘No one,’ he writes, ‘can coerce me to be happy in his way (as he thinks of the welfare of other human beings); instead, each may seek his happiness in the way that seems good to him, provided he does not infringe upon the freedom of others to strive for a like end which can coexist with the freedom of everyone in accordance with a possible universal law (i.e. does not infringe upon this right of another.’ [Kant 1793, 291] He adds, ‘A government established on the principle of benevolence toward the people like that of a father toward his children — that is, a paternalistic government (imperium paternale), in which the subjects, like minor children who cannot distinguish between what is truly useful or harmful to them, are constrained to behave only passively, so as to wait only upon the judgment of the head of state as to how they should be happy and, as for his also willing their happiness, only upon his kindness — is the greatest despotism thinkable (a constitution that abrogates all the freedom of the subjects, who in that case have no rights at all).’ [Kant 1793, 291]”
But this is not the whole story. On the other side of the argument, Kant wrote: “When he came to publish the ‘Doctrine of Right’ some four years later, Kant’s views seem to have shifted significantly towards accepting, even endorsing, state interference in social matters. Now, he says the ruler can impose taxes not just for the defence of the state but ‘to support organizations providing for the poor, foundling homes, and church organizations, usually called charitable or pious institutions.’ Why should those who have more be legally obliged to contribute to the support of those who have less? Because, Kant says, ‘they owe their existence to an act of submitting to [the state’s] protection and care, which they need in order to live.’”
“If freedom is man’s only original right, isn’t this right necessarily infringed upon by the existence and operation of the state? Kant rejects this conclusion. The state indeed employs coercion and that coercion can be taken to be a hindrance to freedom, but the state in using coercion isn’t in fact hindering freedom but merely offering a hindrance to a hindrance to freedom, a hindrance to violence or aggression.”