The five ways and the five second dismissals

After Aquinas formulated his "Quinque Viae," students would often spend weeks studying each "way," as an introduction to these ideas.

Today, students spend five seconds having some professor guffaw, "Ha, if everything has a cause, what caused God?!" (Showing the professor himself has no idea what the second way claims.)

But to take this argument seriously, to spend the time necessary to grasp it, would start to produce doubts: maybe Aquinas was on to something! And we don't want that.


  1. Gene, I've read Feser's explanations of Aquinas' Five Ways, and I've come up with objections to two of the arguments. Here they are:

    Here is my understanding of the First Way:
    1. Motion, defined as the actualization of a potential, exists.
    2. Something cannot be both potential and actual in the same respect.
    3. Therefore, if something is moved (i.e. if one of its potentials is being actualized), that motion must be caused by something else.

    My objection is about the step from 2 to 3. How can you go from the statement that something cannot be potential and actual in the same respect to the conclusion that something cannot move itself? Why can't, say, the hotness of a metal object cause the object to expand? Why can't one actual attribute of an object cause another attribute of the object to go from potential to actual?

    Here's my understanding of the beginning of the Fifth Way:

    1. Some things are transitory
    2. If something is transitory, the sooner or later it will go out of existence.
    3. If everything is transitory, then sooner or later there will be a time when nothing exists.

    My objection is again about the step from 2 to 3. Even if we grant that every individual thing will go out of existence sooner or later, why must there be a time when nothing exists? Why can't it be that as some old things go out of existence, other new things come into existence, in such a way that you never have a situation where nothing exists?

    1. Keshav, if you don't take the time to gain more than a superficial understanding of the arguments here, why do you expect others to spend the time to handle your superficial objections?

      If your objections made any sense, it would mean that one of the greatest philosophical minds of all time maybe very elementary errors in his arguments, that coild be discovered in about ten seconds by A bright young man.

      If you are going to try to grapple with these arguments, it behooves you to study them to the point where you understand them as at least being remotely plausible. Then you might try formulating objections.

    2. Gene, I'm not accusing Aquinas of making elementary errors; I'm just trying to understand his arguments. My understanding of the Five Ways comes entirely from the explanations in Ed Feser's books "The Last Superstition" and "Aquinas". Do you have any recommendations as to what I should read to further understand Aquinas' arguments?

      "If you are going to try to grapple with these arguments, it behooves you to study them to the point where you understand them as at least being remotely plausible." Well, I think I do find the general thrust of these arguments plausible, in the sense that I see their basic internal logic and it seems plausible to me that something along these lines could prove the existence of a god.

      In any case, I'd greatly appreciate it if you could try to explain to me what the flaw is in my objections, or what misunderstandings are leading to my objections.

    3. "Do you have any recommendations as to what I should read to further understand Aquinas' arguments?"

      Keshav, I believe Aquinas wrote a bit on this topic.

    4. I know I shouldn't do this, because I am encouraging the "five second dismissal" mindset, but:

      Keshav, your example one is relies on a bogus distinction to do its work: the heat of an object and its expansion are the same thing viewed in two ways. The question for this "way" is: How did the thing become hotter? It did not heat itself!

      Or if you really want to separate the expansion from the hotness, then you have answered your own question that way: there are two separate things, the heat and the expansion, and one caused the other.

      Either way, what you have offered is evidence Aquinas was right, and not a counter-example.

    5. Gene, how I'm conceptualizing things is that temperature and length are two attributes of the same object, say a metal bar. Now the goal of Aquinas' argument is to prove the existence of an object which has no unactualized potentials, i.e. an object all of whose attributes are actual. And to reach that goal, first he's trying to show that if a potential attribute of an object is being actualized, then that actualization must be caused by another object.

      So consider a metal rod which is currently short but has the potential to become long, and which is currently hot. Then my question is, why can't the actual hotness of the metal rod cause it to change from a potentially long rod to an actually long rod? Why must this change be caused by an actual attribute of something other than the rod?

      By the way, Aquinas stated his Five Ways in extremely brief fashion in the Summa Theologica. I know that he elaborates further on the First Way in the Summa Contra Gentiles, but what should I read to get elaboration on the other four ways?

    6. Are the hotness and the length two things or one thing? If two, case closed. If one, something else caused them both to change.