When therefore we demand whether anything be the same or no, it refers always to something that existed such a time in such a place, which it was certain, at that instant, was the same with itself, and no other. From whence it follows, that one thing cannot have two beginnings of existence, nor two things one beginning; it being impossible for two things of the same kind to be or exist in the same instant, in the very same place; or one and the same thing in different places.He infers from this the impossibility of a soul not existing from the death of its body in 1890 (say) to its rebirth in a different body in 1990 (say). Does this also refute the possibility of time travel? Dr Who gets into his trusty police box in 1999 and travels to the year 2101. He lives out the rest of his life in the 22nd century and never travels to the 21st century. Therefore, Dr Who never existed in the 21st century. But he exists at the end of the 20th, and exists again at the beginning of the 22nd. Is this inconsistent with Locke's maxim about the impossibility of two beginnings? It's odd. The maxim seems correct, and it seems impossible that the same thing cannot have two beginnings. It seems almost a logical truth. Yet the impossibility of time travel does not seem a logical truth at all.
Thursday, June 14, 2012
Is time travel possible?
Maverick quotes John Locke (great English philosopher and father of the American constitution) on the impossibility of two beginnings of existence, as follows.