Hektoen International

A Journal of Medical Humanities

How to acquire something external – Immanuel Kant on kidney-paired donation

Hansjörg Rothe
Würzburg, Germany


Immanuel Kant

Literature in its finest examples stands above time. When Shakespeare wrote Hamlet he could not foresee what our daily life would be like at the beginning of the twenty-first century. Neither could he have dreamt of all those technical innovations mankind would achieve in the 400 years to come, but still we enjoy watching and discussing his play as if he had written it for us. How come that all our motor cars, spacecrafts, and nuclear power plants somehow fit into this plot although Shakespeare did not anticipate them to ever exist? Could it be that the truths he refers to are, at least partially, eternal? Philosophical literature in particular claims to deal with eternal truths, and Immanuel Kant always maintained that what he had written about reason, for-instance, was valid not only for his fellow human companions in time but for all reasonable beings. Not always did his students understand his lectures at the small Prussian university of Königsberg in the late eighteenth century. Kant wrote as if he knew things that they could not even dream of in their wildest imagination – in fact he wrote the Metaphysics of Morals as if he knew that kidney-paired donation would be feasible one day. So we are in a more comfortable position as compared with those students of his – we know KPD does exist, for sure. Let´s enjoy the text, as if it had been written for us – which it was … Enter Kant!


Kant on the acquisition of organs

Part 1 of „The metaphysics of morals“ examines the Doctrine of Right, and its second chapter is headlined: How to Acquire Something External. After two sections “On property Right” and “On Contract Right”, the third section combines aspects of both of the former under the headline “On Rights to Persons Akin to Rights to Things”. Kant argues that there is such a right under certain circumstances, and that “this kind of right is neither a right to a thing nor merely a right against a person but also possession of a person.” People who exert this kind of right stand in “community” with one another and this status may be acquired “neither by a deed on one´s own initiative (facto) nor by a contract (pacto) alone but by a law (lege).”1 Kant points out that such laws – resulting in not “merely a right against a person but also possession of a person” – are associated with the acquisition of certain objects, and his first example is: marriage…. Kant defines marriage as a “sexual union in accordance with law”, i.e. “the union of two persons of different sexes for lifelong possession of each other´s sexual attributes”, or in other words: “the reciprocal use that one human being makes of the sexual organs and capacities of another (usus membrorum et facultatum sexualium alterius).”

Kidney-paired donation, on the other hand, is the union of two couples for lifelong possession of each other´s donated kidneys, a community characterized by the reciprocal use that one donor-recipient couple makes of the donated kidney of another couple – condition for the lawful act establishing this community is the sincere wish of both couples to have a kidney donation performed between the partners, but due to HLA incompatibility the donations cannot be done directly between the partners but only in a cross-over between the couples. This corresponds to Kant´s definition – the only reason why he does not mention organ donation at this point is that it was still technically impossible to perform at his time. What he refers to is a lifelong reciprocal possession of each other´s organs – this is what kidney-paired donation is all about, only that it is not the sexual organs that are exchanged in KPD, but kidneys.

What does that mean for marriage? Unlike Kant, who knew divorce as a rare exception, sometimes practiced for dynastic reasons in noble families only, we tend to think of marriage as a community which can be revoked any time. One might argue that KPD is in fact more similar to the 18th century way of marriage than to marriage today, in that a “divorce” is pretty much unheard of in kidney-paired donation. In our line of thought this could mean, that the quality of community in a relationship should be defined by the sincere wish to donate a kidney to the partner rather than the condition to be of different sexes. The meaning of ”marriage” has changed over time, and as always we have to make sure to preserve the essence instead of clinging to the mere shape.

But interestingly, marriage is in fact only Kant´s first example. He goes on to distinguish all together three kinds of objects that may be acquired “in accordance with this principle”: 1) A man acquires a wife (Later in the text this acquisition is qualified as reciprocal, so that the woman acquires her husband, too ). The other two examples are: 2) A couple acquires children, and 3) A family acquires servants. While we can agree with the second example to a certain point, the third one strikes us as being too close to slavery. However, we should bear in mind that our modern societies are really organized in a way that makes it quite difficult for many couples to work and raise a family at the same time – couples with children, who are fortunate enough to spend sufficient time together as families, should at least consider from time to time that their happiness was made possible by those “servants” who work full-time but cannot have families of their own.

And as far as Immanuel Kant is concerned, the human being he had lived together with for most of his adult life was his man-servant of forty years Martin Lampe – anecdote has it, that Kant was very surprised to learn after decades, that the former Prussian soldier was in fact married.


On community and rejection

When Felix Rapaport introduced the concept of kidney-paired donation in 1986,2 the technique had finally reached a stage where the transplantation of a kidney between genetically unrelated spouses had become safely possible in many instances – however, even today the genetic compatibility between donor and recipient may still be insufficient for the procedure to be performed. In these cases, Rapaport argued, a second pair in the same situation might be found so that cross-over transplantations from the donor of pair A to the recipient of pair B and vice versa could be feasible. When he introduced the term “emotionally related” to describe the pairs of potential kidney donor/recipients, Rapaport made himself an important contribution to the metaphysics of morals although he was a surgeon rather than a philosophy professor. But this is no surprise given how far modern medicine has already pushed the boundaries of the technically feasible towards the eternal questions of life and death. In his personal life Felix Rapaport had to face those questions, too, when he nearly died of hepatitis as a fourth-year medical student. This experience apparently influenced his decision to specialize in transplantation surgery. But much earlier, at the age of six, he had had to learn already what misery perverted views of community can bring on other people: He and his family had been rejected from his home town Munich and the country of his birth – because too many of their fellow Germans claimed to speak Kant´s language but made only insufficient efforts to understand the Metaphysics of Morals.

Reaching the end of this literary vignette, we should note that the concept of “community” is really inseparable from the eternal enigma of life and death. Enter Hamlet: “To be or not to be …” is a question people of all centuries and continents have had to face, essentially it remains the same although it comes in different shapes. Let us stay in touch with our past, while we practice medicine in our days, so that the future may be bright.



  1. Immanuel Kant „The Metaphysics of Morals“, translated and edited by Mary Gregor, Cambridge University Press 1996.
  2. The case for a living emotionally related international kidney donor exchange registry. Transplant Proceedings1986 Jun;18(3) Suppl. 2):5-9.



HANSJÖRG ROTHE, MD, was born in Leipzig, Saxony, in the former German Democratic Republic. He attended school at Francke´sche Stiftungen Halle and was a medical student at Martin Luther University Halle, where his medical thesis was on pathobiochemistry. He has practiced as a medical doctor since 1994 in Germany and the UK, and is board certified in internal medicine and nephrology. His research interest is in pharmacogenetics, and he has been involved in a pharmacogenetic project at Brookdale University Hospital & Medical Center in Brooklyn, New York from 2002-2005 with a research fellowship grant from AMGEN. Currently, he conducts clinical work at Klinikum Coburg and research at the University of Würzburg in Germany.


Spring 2015  |  Sections  |  Nephrology & Hypertension

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