A thesis at the heart of Kant’s entire philosophy is that the things we see before our eyes are only appearances of what they are really like, in themselves, independently of human perception or experience. These things can thus be conceived as belonging to two worlds: a sensible world, containing what we experience; and a world of understanding, that we can only think. The latter is sometimes called the intelligible world (Kant 1997, 56-7/4:451-2), and the two worlds are distinguished also as the phenomenal and noumenal worlds (Kant 1998a, A235-60/B294-315). We see that we belong to the two worlds also, when we consider that the way we appear to ourselves (and others) is not the way we really are, in ourselves.

Standpoints vs. worlds. It has been common recently for Kant’s interpreters to downplay the importance of his talk about different worlds, and to explain that what he must really have meant is only that there are different standpoints, or perspectives we can take on things: the noumenal and phenomenal standpoints (see, e.g., Allison 1990, 3-4; Korsgaard 1996, 203). But I favor an opposite interpretation, which is that the two standpoints are a kind of shorthand reference to the two worlds (McCarty 2009, 105-29). It is important to understand what Kant meant by a “world.” He defined a world as a whole that is not a part of a larger whole. Implicit in this idea of a whole is that it contains a plurality of elements, each of which stands in connection with every other—the connection of elements is what makes the plurality a “whole,” rather than simply an aggregate or totality. All material objects are connected by the force of gravity, for example. Everything material exerts its gravitational pull on everything else. So if material objects are not part of a larger whole—if they are not affected also any immaterial minds—then they can all be conceived as belonging to a “material world.” For the sensible world, generally, all of its elements are connected by the relations of space and time. Since talk about different standpoints misses the essential connections among the elements of different worlds, it does not convey the same meaning as talk about worlds. So it is best to interpret Kant’s talk about standpoints as merely derivative: as derived from his more fundamental conceptions of the two worlds.

Where is the intelligible world? This is a little like asking what time it is on the sun. The intelligible world isn’t anywhere; the sensible world isn’t anywhere, either. Kant argues that space and time belong only to the sensible world, so if there is a world that is not sensible, then there is no reason to think of it as somewhere in space. Nor is the sensible world somewhere in space. As the totality of all that can be experienced by human beings it is not in space. Rather, spatiality, and temporality, belong to it.

Freedom in the intelligible World. We can see ourselves as members of the sensible world, obviously; so we can also consider ourselves as we really are, apart from how we appear in space and time. So considered, we would be independent of the order of things where everything that is done or happens is preceded by a prior cause. Hence, in the intelligible world we would be free. It might seem that our freedom there, without time, would be pointless. But there is no reason to think we could not act in a timeless world (see McCarty, 2009). In order to be a member of such a world we would have to be connected with everything there, and so affect everything there. For this reason, our very membership in an intelligible world could mean that the difference we make there is up to us—that we belong the intelligible world by acting there. Then, if the sensible world is the appearance in space and time of the intelligible world, the contribution we would make to the intelligible world must appear in the sensible world. What we do freely there, in other words, must appear here, spread out in space and time.

The hidden circle revisited. Before raising the prospect of the two standpoints Kant suggested that he might have been arguing in a circle: that we assume we are free, in order to act morally, and then conclude that we are free, because we are subject to the moral law. This is a circle because freedom and morality are reciprocal concepts—so we cannot argue from one to the other. We need to argue independently for one, so that the other will follow. The explanation of the two standpoints, actually, the two worlds, provides the independent argument for our freedom, and thus for our subjection to moral laws. By recognizing that we exist independently of sensible conditions, in an intelligible world that is the basis for the appearance of the sensible world, we recognize that we are free of natural, space-time causality. Kant writes: “when we think of ourselves as free we transfer ourselves into the world of understanding as members of it and cognize autonomy of the will along with its consequence, morality” (1997, 58/4:543).

Noumenal action and the sensible world. How can our free actions in the noumenal world make a difference in the causally determined phenomenal world? Kant is often criticized on this point, by people who do not, I think, understand his view. Ross provides a good example:

Against [Kant’s view] we must say that the recognition of a particular duty...takes place in time, and is a link in a chain of causes and effects, though not of physical causes and effects merely. Nor does [Kant] do justice to moral considerations. For instead of showing that we can act either from sense of duty or desire, he makes out that from one point of view we always act from sense of duty, and from another point of view from desire. To say this is to obliterate the distinction between good and bad acts. (1954, 85)

Though it is not emphasized in the Groundwork, Kant’s view is that all of our actions in the sensible world depend on our empirical characters (see 1998a, A549/B577), and that our characters are appearances of our contributions as free agents to the intelligible world (A438/B566ff). So although it is true, as Ross says, that we recognize some action as our duty in time, whether we do it or not, in time, depends on our empirical character. As far as what he above calls “moral considerations,” he is mistaken in his assumption that in the intelligible world, or viewed from the noumenal standpoint, we cannot fail to do our duty—that we always act from “sense of duty.” First, duty is not part of the noumenal world, but belongs in the sensible world. Kant writes that “if we think of ourselves as put under obligation we regard ourselves as belonging to the world of sense (1997, 58/4:543). Second, there is no reason to suppose that, as noumenal agents, our actions are morally perfect. Kant’s view was that if we were only members of the noumenal world, then all of our actions would conform to perfectly to the moral law (1997, 58/4:453); but our being part of the world of sense, also, implies that we do not necessarily do our duty—duty, again, belongs to the world of sense. Kant deals with the prospect of what he calls “radical evil” in his book on religion, where he explains that human beings are evil (morally imperfect to various degrees) because of their own deeds apart from the world of experience (Kant 1998b, 61-5/6:39-44).

Allegory of the play. I find it helpful to explain Kant’s theory of action in two worlds by imagining an actors’ workshop (McCarty 2009, 152-4). In this allegory, each member of troop of players specifies a list of character traits, and a playwright then composes a play including characters with those traits. Subsequently, each player performs his or her chosen character in the play. The play represents the sensible world, where all of our actions on the sensible stage are “in character,” so to speak, and where everything has a cause, as in determinism, and where we virtually follow a script throughout our lives. The workshop represents the intelligible world, where we freely specify the characters we shall play, independently of the play-world, of which we have no knowledge. So in this way there is a clear sense in which what we do in the play of the sensible world is always determined by circumstances beyond our control; and yet, to the extent that we are responsible for our characters, we are responsible for what we do in those circumstances.