Are you asking for a defense of the statement, or do you agree with it and are merely commenting on the way I expressed it?
I’ll give a defense by means of an example. At Wikipedia they give the following example of a counterfactual:
If Oswald had not shot Kennedy, then someone else would have.
Now consider the equation F=ma. This is translated at Wikipedia into the English:
A body of mass m subject to a force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma.
Now suppose that there is a body of mass m floating in space, and that it has not been subject to nor is it currently subject to any force. I believe that the following is a true counterfactual statement about the body:
Had this body (of mass m) been subject to a force F then it would have undergone an acceleration a that would have had the same direction as the force and a magnitude that would have been directly proportional to the force and inversely proportional to the mass.
That is a counterfactual statement following the model of the wikipedia example, and I believe it is true, and I believe that the contradiction of the counterfactual (which is also a counterfactual, i.e., the claim that the body would not have undergone the stated acceleration) is false.
I believe that this point can be extended to all the laws of physics, either Newton’s laws or, if they have been replaced, modern laws. And I believe, furthermore, that the point can be extended to higher-level statements about bodies which are not mere masses moving in space, but, say, thinking creatures making decisions.
Is there any part of this with which you disagree?
A point about the insertion of “I believe”. The phrase “I believe” is sometimes used by people to assert their religious beliefs. I don’t consider the point I am making to be a personal religious belief, but the plain truth. I only insert “I believe” because the very fact that you brought up the issue tells me that I may be in mixed company that includes someone whose philosophical education has instilled certain views.
Are you asking for a defense of the statement, or do you agree with it and are merely commenting on the way I expressed it?
I’ll give a defense by means of an example. At Wikipedia they give the following example of a counterfactual:
If Oswald had not shot Kennedy, then someone else would have.
Now consider the equation F=ma. This is translated at Wikipedia into the English:
A body of mass m subject to a force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma.
Now suppose that there is a body of mass m floating in space, and that it has not been subject to nor is it currently subject to any force. I believe that the following is a true counterfactual statement about the body:
Had this body (of mass m) been subject to a force F then it would have undergone an acceleration a that would have had the same direction as the force and a magnitude that would have been directly proportional to the force and inversely proportional to the mass.
That is a counterfactual statement following the model of the wikipedia example, and I believe it is true, and I believe that the contradiction of the counterfactual (which is also a counterfactual, i.e., the claim that the body would not have undergone the stated acceleration) is false.
I believe that this point can be extended to all the laws of physics, either Newton’s laws or, if they have been replaced, modern laws. And I believe, furthermore, that the point can be extended to higher-level statements about bodies which are not mere masses moving in space, but, say, thinking creatures making decisions.
Is there any part of this with which you disagree?
A point about the insertion of “I believe”. The phrase “I believe” is sometimes used by people to assert their religious beliefs. I don’t consider the point I am making to be a personal religious belief, but the plain truth. I only insert “I believe” because the very fact that you brought up the issue tells me that I may be in mixed company that includes someone whose philosophical education has instilled certain views.
I am merely commenting. Counterfactuals are counterfactual, and so don’t “exist” and can’t be “there” by their very nature.
Yes, of course, they’re part of how we do our analyses.