If Oswald didn't shoot JFK, then someone else did.
If Oswald didn't shoot JFK, then someone else would have!
If the match had been scratched, it would not have lighted.
If you had exited the other side of the bed this morning, you would have solved the problem of counterfactuals.

A Counterfactual is a type of conditional statement of the form: If (something which is not the case) were true, then some state of affairs would be the case. The antecedent is "counter" to "fact". How are we to evaluate the truth-values of these sorts of conditionals? How could we ever have a systematic method for evaluating their likelihoods? Why should we care?

Statements of this sort are ubiquitous in our lives, from philosophy, to politics, to science, to relationship arguments, to self-pitying depression, on and on. And yet, when we look closely and philosophically at them, there are some serious problems.

I am going to do a short presentation of "Two Problems of Counterfactuals" from Nelson Goodman's classic work Fact, Fiction, and Forecast where he argues firstly that counterfactuals are integral to us, as well as perhaps burdened with unsolvable problems.

Then I will take a look at David Lewis' "Possible Worlds" suggestion from his Counterfactuals, one of the most widely respected potential solutions.

From here, we can go in depth as a group and discuss what we think of these strange creatures. Bring your cogi-taters.