Suum and synallagma

In my other blog journal for my Divisions of Law project, I added an entry a while ago discussing the 'Synallagmatic Theory of Contract.'  This was introduced by the French legal systematist, François Connan, and then appropriated by Jean Bodin in his Distributio of law.  

Recently, I've been returning to this notion of the 'synallagma' in the history of contract law.   It is particularly important in Roman law (at D.50.16.19), because Ulpian famously cites a text by the jurist, Labeo, who defines 'contract' [contractus] as a mutual obligation [ultro citroque obligatio] - itself an unconventional definition, since some contracts can be, in principle unilateral and gratuitous.  

But the most interesting feature of Labeo's text is how he explicitly identifies contract as equivalent to the Greek συνάλλαγμα.

The term, συνάλλαγμα, is especially striking, and I believe an intentional gesture on Labeo's part.  For experts in moral philosophy, the term should be immediately familiar.  

It is a key ingredient in Aristotle's theory of commutative justice.  Rackham's translation in the Loeb Classical Library renders συνάλλαγμα as 'private transactions,' but it is in the places where one observes and experiences commutative justice that the significance of this for civil law can be observed.

Aristotle distinguishes between transactions that are voluntary (which really are contracts) and those that are involuntary.  But for students of Roman law, the arrangement should look familiar, because it is the inspiration (or at least it has been conjectured) for Gaius's famous arrangement of the Law of Obligations (Gaius 3.88):

'Obligatio ex contractu' and 'obligatio ex delicto.'  

But the most important point in Aristotle's theory of commutative justice is maintaining equality in a συνάλλαγμα-exchange.  A simple contract of sale nicely illustrates this point.  It would be a (commutative) injustice if I paid too much for some good.  The seller would unjustly benefit at my expense, producing an inequality in exchange.   I would, in principle, be entitled to seek the amount that is still due to me.  And, indeed, civil law empowers individuals to sue in court in such cases - in this case, the Actio Empti or the Indebitum suit.

This is perhaps easiest to observe in commercial exchanges, like a sale or a hire.  But the point needn't be strictly commercial in the marketplace.  Justice isn't fundamentally about getting paid, but instead, about getting what is due to you.  And this is why Roman lawyers understood justice about what is 'due':

'Justice is the constant and perpetual will of rendering unto each his due.'  His SUUM.

Now, I have several things I want to say about this very transactional, very interpersonal (and - I stress above all - very un-Rawlsian) way of thinking about justice.  But one of them brings me back to Grotius, to the passage that I have been thinking about now for over a year (I think I discussed this in some earlier posts in this journal):

Grotius 1.1.5: 'The jurisconsults call 'Facultas' by the name SUUM:  We shall hereafter call this 'Right properly or strictly so called' (Barbeyrac called it 'droit rigoreaux').

This is a critical moment in the history of correlative rights and duties.  SUUM originates as an idea about what is due.  Grotius flips it around and calls it a right, probably on the reasoning that if something is owed to someone (like the debtor's repayment of the balance on a debt), it can be claimed as a right (by the creditor).

But it is not only in the Law of War and Peace.  Grotius's outline of Roman-Dutch law makes essentially the same point, identifying TOEBEHOOREN (his equivalent to SUUM or 'strict rights') as encompassing both claims arising from property and obligation.

What I see Grotius doing, however, is that he is moving outside the marketplace.  'Suum cuique tribuere' needn't be only about unpaid debts or borrowed property.