Contra Counterfacts

Prof Alan Hájek (Australian National University)

Alan Hájek (ANU) will present "Contra Counterfacts". The talk will be at 2pm in G14 Old Quad.

Abstract: ‘If Oswald hadn’t killed Kennedy, then Kennedy would have lived to the age of 81 years and 269 days.’

‘If I were to toss this coin 1000 times, then it would land 572 heads’.

These counterfactuals presumably are not true with the exact numbers that I have used. But according to an increasingly influential view, there are true counterfactuals just like them—there are exact numbers that render them true. The view goes back to the Molinist doctrine of God’s ‘middle knowledge’; but versions of it are becoming increasingly influential thanks to recent papers by Hawthorne, Moss, and Stefánsson. On Stefánsson's version, for example, there are primitive modal facts—what he calls counterfacts—that serve as truth-makers for counterfactual claims. To be sure, we are typically ignorant of such counterfacts (unlike God, according to the Molinists); yet we may often have good evidence of them—or so Stefánsson argues.

I have long argued that most counterfactuals are false, either because of indeterminism or indeterminacy. The thesis that there are counterfacts, if true, would defang my arguments. But like the counterfactuals themselves, the thesis is false—or so I shall argue.