Kant's question, How are synthetic a priori judgments possible? creates significant difficulties for subsequent generations of 'moderns' like ourselves. The wording of the question may appear obscure, but it gets at a something very basic that we take for granted everyday. It asks how is it possible for us to be confident in our methods of natural scientific study. How do we know that our conclusions correspond to objective reality? The way that Kant formulates the question, however, assumes that the human world could be divided into two distinct parts: between 'the starry heavens above' and 'the moral law within.' By the former Kant meant the whole order of nature, everything in the spatiotemporal world; and by the latter he meant something like a universally accessible, rationally determinable standard for moral conduct. This should sound familiar to anyone familiar with the distinction that people like to draw between facts and values.
The problem that Kant's formulation could not overcome, as we saw last time, was that moral judgments always pertain to specifically human thought and action, which is always locatable somewhere in space (or place) and time. Moral judgments do not 'terminate' in an abstracted universal idea of what human beings ought to be or ought to do, but concretely in human bodies. A moral judgments, in this sense, bridge the the gap between the realms of fact and value. It ascribes moral value to what would otherwise seem a merely empirical reality. The moral injunction against murder (or rape, or theft, or lying), for example, seems to be stated in abstractly universal terms. Don't murder: full stop. But the injunction only makes sense as a moral injunction if it universally applies in every individual instance: that is, to actual living, breathing human beings. Assenting to the abstract truth that one ought not murder one's fellow human beings and then going out and murdering actual people is only moral in the sense that it is a violation of the moral norm.
One of the most persuasive solutions to Kant's question was offered by G.W.F. Hegel in a little studied section at the very beginning of his Phenomenology of Spirit titled 'Sense-Certainty.' In effect, what Hegel claims is that Kant misunderstands the moral nature of human embodiment.
Let's do a brief recap. Kant claimed all of human knowledge was the product of one of three types of judgment: analytic a priori, synthetic a posteriori, and synthetic a priori. These are as follows:
Analytic a priori judgments are those sort of judgments that you can make in and of itself without reference to anything 'external.' Examples would include 'triangles have three sides' and 'mothers have children.' The predicate of the statement ('three sides,' 'children') is already contained in the subject of the statement ('triangles,' 'mothers'). To wit: a triangle isn't a triangle if it doesn't have three sides and a mother isn't a mother if she doesn't have children.
Synthetic a posteriori judgments, by contrast, are those judgments that you make by reference to something else. Examples would include 'the grass is green,' 'I am 33 years old,' and 'the weather is cold for the time of year.' These things might be true. They also might not be true. Whether they are true might change from place to place and time to time. Late in the fall, the grass is die and turn brown. Next year at this time, I will be 34 years old. And if I step outside, I might discover that the weather is quite pleasant, about what a person excepts for the time of year.
The third category of synthetic a priori judgments bridges the gap between analytic a priori judgment, which are necessary (always and everywhere the same), and synthetic a posteriori judgments, which are contingent (which might vary from place to place and time to time). It tries to make sense of the predictive ability of natural scientific claims. For example, we are able to determine that objects fall at 9.8 m/s2 near the earth's surface. We don't have to keep on verifying this fact ad nauseum. It doesn't need to be tested over and over again in order to determine that it is still true. We can demonstrate it, confirm it, assume it, and then move onto other more complex questions.
Hegel noticed what has already been pointed out: that Kant's three categories of judgment could not locate specifically human thought and action anywhere specifically within the spatiotemporal universe. His three categories of judgment were abstract in the sense that they were judgments of an ideal knower who was unrestricted by place and time, not an actual knower (like yourself or myself), who is restricted by place and time. That was (and still should be) genuinely perplexing. If you think about yourself, you will immediately notice that all your thought and action is tethered to your particular bodily existence.
Consider that you can think about and do many things. You can even think about (though not do) everything. But you can neither think about nor do anything without taking into account a fundamental relation between, on the one hand, your subjective thought, and on the other hand, and your particular objective situation. I might reflect, for example, for a moment on the 'Big History' of the universe, which is billions of years old and tens of billions of light-years across. I would have done so, however, in particular places and times--maybe by reading a book or by joining an online course and watching Youtube videos.
Hegel makes roughly this argument in the Phenomenology. He notices that all our thoughts about object in the world contain a reference to an 'I' which thinks, a 'This' which designates the thing being thought about, and a 'Here' and a 'Now' in which the 'This' is situated. So, for example, you (the 'I') might be thinking about a tree or a house or your wife (the particular 'This' in question). Regardless whether you were are thinking about the tree, the house, or the wife, your thought about 'This' has a 'I-This-Here-Now' structure.
Note the comparison to Kant's different forms of judgment. Hegel's 'I' never changes. It is always you (or always me) who is doing the thinking. In this sense, the 'I' is necessary like Kant's analytic a priori judgment. But the reference of Hegel's 'This-Here-Now' can and does change. If you let your mind wander from This (what you had for breakfast this morning) to This (what you need to pick up from the store after work) to This (the funny line from the movie last night), you will see what I mean. The 'This-Here-Now' is therefore contingent like Kant's synthetic a posteriori judgment.
Hegel uses the generic examples of day and night to illustrate the point he wants to make. He says, 'To the question, "What is Now?", let us answer, e.g. "Now is Night."' He continues, 'In order to test the truth truth of this sense-certainty a simple experiment will suffice. We write down this truth [since] a truth cannot lose anything cannot lose anything by being written down.'
So we write down 'Now is Night.' But now we have a problem. Time passes us by, night becomes day. What we have written down will no longer be strictly true. It was true when we wrote it down. It is no longer true. What was is no longer. Or, in the technical terminology that Hegel uses, Being has passed over into Non-Being.
Hegel repeats the demonstration with the examples of a house and tree. He says, 'The same will be the case with the other form of the "This," with "Here". "Here" is, e.g., the tree. If I turn round, this truth has vanished and is converted into its opposite: "No tree is here, but a house instead".'
No reference is made to writing down the word tree in order to test the truth of the assertion this second time around. Still, Hegel's basic point remains the same. As our perception alights on a different 'This-Here,' what was is no longer. Being has once more passed over into Non-Being.
There is a more sophisticated analysis of Hegel's argument which would point out that our perception of things in space differs from our perception of the same things in time, where Hegel seems to treat them as fundamentally equivalent. This line of inquiry would problematize the argument considerably--and needlessly at this point. Our interest will remain with what Hegel actually does say. We want to know what he does say about the complex 'I-This-Here-Now.'
Well. Stuff very quickly gets strange. One would expect Hegel to say he has found a complex, concrete universal, something a person can take with themselves everywhere and apply to every situation they find themselves in. Thinking about buying a house? 'I-This-Here-Now.' Thinking about breaking up with your girlfriend? 'I-This-Here-Now.' Wondering where you are going to vacation in the summer? 'I-This-Here-Now.' And so on, and on, and on, and on, ad infinitum (or until the moment that you fall asleep or that you die).
But Hegel doesn't do this. Or, if he does, he doesn't make it easy for his readers to see him doing this. So what does Hegel actually do? He applies what is known as the logic of 'the negation of the negation' to his argument. Returning to his examples for 'This-Now' and 'This-Here,' he points out that in both cases the 'This' passes over into 'Not-This.' Night becomes day. The tree is now the house. This is the first step of 'the negation of the negation': Being becomes Non-Being. What was is no longer. The day is not the night. The house is not the tree.
But we need to step back, so to speak, and reflect on what has occurred. Hegel also wants us to note carefully what has happened: the Not-This is not simply a Not-This. It is a This in its own right. This was night. This was a tree. In actual fact, however, This is now the day or a house.
The new 'This-Now' or the new 'This-here,' in their turn, these too pass over into 'Not-This.' Either time passes and/or a person's attention wanders to something else. This is the second step of 'the negation of the negation': The new This is itself negated, and becomes 'Not-This.'
Here is the really perplexing part. You would expect that Hegel would simply repeat the procedure over and over again, showing that This becomes Not-This, which which is shown to be a This in its own right, which becomes Not-This, and so on, and on, and on. It wouldn't matter what particular things you were thinking about. The 'I-This-Here-Now' structure would be recycled over and over again to make sense of every new thought that a person has about different things.
But Hegel argues that all you need demonstrate the logic of 'the negation of the negation' is two negations. Additional negation would both be superfluous and distract from the essential lesson. Two negations are all that is needed to demonstrate I am not actually thinking about particular things, but a universal 'This-Here-Now,' which I discern in and through particular things. The 'externals' might change; the essentials do not. And this means, Hegel says, that every particular 'This-Here-Now' is implied in every other 'This-Here-Now.' The entire spatiotemporal universe, and every particular thing in it, is joined together in this complex, concrete universal thought, which every person carries around with them in their own heads.
So where does Hegel leave us? He sees the deficiency of Kant's formulation of the question, How are synthetic a priori judgments possible? He sees that human thought and action must, in principle, be locatable in the spatiotemporal world. Even so, it is still not clear whether he leaves persons in the position of an ideal knower (a divine being), who knows all things in all places and all times in exactly the same way. In this case, the whole of human history will simply be the story of God's thoughts and actions manifesting themselves in and through human lives. But he might also leave persons in the position of an actual knower (a human being), who knows things in particular places and particular times in exactly the same way. In this case, the whole of human history is made of up human thoughts and actions, which manifests themselves in and though human lives.
Which reading is correct is not entirely clear from the actual wording of Hegel's text. Both readings commend themselves in different ways. The former reading, which sees Hegel claim to occupy the position of an ideal knower, has been the default reading of Continental philosophy down through the 19th and 20th centuries. Nietzsche, for example, famously derided Hegel for assuming that the whole of human history culminated in his own Berlin existence. The latter reading, which sees Hegel describing the situation of an actual human knower, is the reading given by Anglo-American idealists, or Progressives, at the end of the 19th and the beginning of the 20th centuries--a group fo thinkers who have largely been forgotten. The latter reading crops up from time to time, most recently in the work of the former Archbishop of Canterbury, Rowan Williams. Otherwise, it has fallen out of favour.
The problem, however, is one worthy of further reflection. We moderns, following Kant, have gotten into very bad habits when we try to think of facts in relation to values. We cite scientific studies at each other when it is convenient, and take principled stands when it is not. Starting from what we share in common, a bodily situation, may help to cut through some of the bullshit.