This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.
Dear Dr. Craig
I was reading the part of your book "Time and Eternity" that talks about perdurantism, and I have a question over your objection to the Perdurantist's view of personal consciousness.
You claim that on Perdurantism, personal continuity from moment to moment is an illusion and that they believe that I was a different person one second ago than I am now, which you claim to be absurd.
However, it appears to me that by the same token, we can argue against Presentism, because Presentism states that only the present exists. But this seems absurd since I can clearly remember me existing one minute ago, yet on Presentism it states that I didn't exist one minute ago. Also, you use our experience of us enduring through time as first hand proof of endurantism, but I find a hard time reconciling this with presentism claiming that we don't exist in the past.
Hopefully you can clear up any misconception that I have on this topic
Yours in Christ,
Dr. William Lane Craig’s Response
For those who are unfamiliar with the terms of your question, Ethan, allow me to explain that perdurantism is the view that persons are actually four-dimensional objects, extended in time as well as space, sometimes called spacetime worms (perhaps giving new meaning to the Psalmist’s lament “I am a worm and no man!” Ps. 22.6). These spacetime worms can be divided into slices in time and so have temporal parts as well as spatial parts. So what appear to us to be people are really just three-dimensional slices of four-dimensional objects. Since these temporal parts do not endure through time but just exist at their respective coordinates, nobody endures through two moments of time: you are literally a different individual than the individual who began reading this response. This seems crazy, not to mention theologically problematic.
Presentism, by contrast, holds that objects do not have temporal parts but exist wholly at a time. So I exist now and endure through time to another moment.
You say that presentism also seems absurd, “since I can clearly remember me existing one minute ago, yet on Presentism it states that I didn't exist one minute ago.” Here your neglect of tense betrays you. When you say that you remember you existing one minute ago, the present-tense participle “existing” is misleading. What you remember is that you existed (past tense!) one minute ago. The presentist affirms that! You existed one minute ago and have endured to the present moment at which you exist (present tense). So you’re mistaken in thinking that presentism holds that you didn’t exist one minute ago. Of course you did; and you will exist (future tense) one minute from now.
Similarly, you neglect tense when you complain that “our experience of us enduring through time” is hard to reconcile with the claim “that we don't exist in the past.” What the presentist claims is that we did exist (past tense!) in the past, and that claim is fully compatible with the claim that we have endured to the present. So long as you keep your tenses straight, there’s no problem.
This post and other resources are available on Dr. William Lane Craig's website: www.reasonablefaith.org