I was fortunate enough to run across David Manley’s homepage today, which includes a list of very interesting papers.  One paper in particular, A gradable approach to dispositions (with Ryan Wasserman), looks at explaining what it means for one glass to be more fragile than another.

The approach taken involves recognizing two distinct parts of a disposition – its triggers and its manifestations.  Let’s say you enumerate all the ways a disposition can manifest, and call that the trigger-space for a disposition (my words, not theirs).  You can then base a scale for measuring the magnitude of something’s disposition on the size of the part of the trigger-space that leads to this thing manifesting the disposition.

For example, let’s take a glass and assess its fragility.  We might define its trigger space based on a range of heights from which we can drop it (e.g. 1 foot, 2 feet, 3 feet) and a set of surfaces (e.g. my pillow, my kitchen table, and the carpet in my living room).  So we have a two-dimensional trigger space with nine possible combinations.  If the glass would shatter from every height on my kitchen table, from 3 feet on my carpet, and never on my pillow, then the measurement would be based on the ratio 4/9 (depending on the choice of units).

This is a pretty cool idea that can be immediately applied to an analysis of retaliation.  I enumerate the various ways that a retaliation can be triggered/provoked, and identify what the manifestation can look like (there’s a separate issue whether a disposition can manifest in different ways – I lean towards yes, but I’ll leave the discussion for another time).

Empirical testing for agentive dispositions like retaliation (i.e. dispositions whose manifestations depend on some conscious decision) are a little trickier than physical dispositions like fragility: you can’t depend on the same triggers leading to the same results every time.  However, the core idea remains the same – by tallying the times that a trigger is followed by a manifestation, a measure of tendency for that can be established.

I’ve only read through the paper once, so I could very well be missing some key points.  And I wonder about the ability to define dispositions that don’t have obvious triggers (e.g. the disposition to yawn, which at first glance seems to be a spontaneous event that happens more or less frequently).  Heck, it seems that E.J. Lowe has reason to think that dispositions don’t even have triggers.  Nevertheless, I think Manley and Wasserman’s paper is pretty damned interesting.