At PrawfsBlawg, Doug Berman has a nift post entitled Can a decision be made "for no reason at all"? The question is whether it is possible to "make a decision" for "no reason at all." Here’s a taste:
A draft article I read about prosecutorial discretion noted that courts are disinclined to scrutinize choices not to prosecute. One court was quoted as declaring that prosecutors could decline to prosecute "for any reason or for no reason at all." This phrase rang a bell; I recall other areas in which courts say some decision may be made "for any reason or for no reason at all." This phrase also led me to ponder a (silly?) metaphysical question: is it really possible to make a decision for no reason at all?
If I can add just a teeny time distinctions. It is clearly possible to act for no reason at all. We do this all the time. Reasons come into play when there is deliberation, contemplation, or decision–but action does not require these. There is, however, something quite odd about a decision for no reason at all: because it is difficult to imagine the process of decision without reasons of some kind coming into play. Of course, "no reason at all" need not be interpreted literally. For example, flipping a coin could be "no reason at all" in a certain sense. Of course, when the coin comes up heads and the decision is taken on that basis, there is a reason: my reason for action was the result of a random process, but that kind of a reason is, in another sense, "no reason at all," because it makes the decision arbitrary. The decision becomes like "an action without a reason," because it lacks the kind of reason that provides justification.
This points us in the right direction, I think. "No reason at all" can be parsed as "No justification at all" and then the puzzle disappears. More on this:
Of Reasons and Causes (And Beating a Dead Horse?) by Jeff Lipshaw.
On No Reasons and Mixed Reasons by Russell Covey.