**time travel**

the self-visitation paradox

x is a **temporal part **of y at t =df (i) x exists only at t, (ii) x is a part of y at t, and (iii) x overlaps everything that is a part of y at t.

**The 4D View**: Objects exist at different times in virtue of having different temporal parts at those times.

**The 3D View**: Objects exist at different times in virtue of being wholly present at those times (i.e., not in virtue of having different temporal parts at those times).

**definitions**

4.

5.

6.

1.

2.

3.

Time travel is possible.

If time travel is possible, then self visitation is possible.

If self visitation is possible and the 3D view is correct, then either

(a) Hector=(Hector1+Hector2) or

(b) Hector=Hector1=Hector2.

It is not the case that (a).

It is not the case that (b).

[So] The 3D view is not correct.

**the self-visitation paradox**

x is F at place p at time t =df there is some y such that (i) y is a part at x at t,

(ii) y exists at p at t, and (ii) y is F at t. x is F at place p at time t =df (i) x exists at p at t and (ii) x is F at t.

**definitions**

x is a **temporal part **of y at t =df (i) x exists only at t, (ii) x is a part of y at t, and (iii) x overlaps everything that is a part of y at t.

x is F at t iff x’s temporal part at t is F.

**definitions**

1.

2.

3.

4.

5.

Time travel is possible.

If time travel is possible, then self visitation is possible.

If self visitation is possible and the 4D view is correct, then

(a) Hector isn’t thinking at t2 and

(b) Hector isn’t a person at t2 and

(c) Hector doesn’t visit Hector at t2.

It is not the case that (a) or (b) or (c).

[So] The 4D view is not correct.

**the self-visitation paradox: v2**