The definition of chance

Aristotle defined chance as a cause per accidens, happening for the lesser part. What does this mean?

When a lion chases down a gazelle and kills it, there was a causal relation between the end and the process that led to it. But events don’t come with name tags on them, and so, looking at this happen, we might have said “look, the lion chased down the light-colored thing”. In this case, however, there is no connection between the end (killing a light-colored thing) and the process leading to it. It is accidental, or per accidens. Depending how we account for the experience, the process we experience might be chance or not. But it’s clear that the thing we are experiencing, depending on how it is accounted for, can either be 1.) a process where the end was a cause of the process, or 2.) where the end is not a cause of the process. 2 are events where the end causes per accidens.

There is more than one way to discriminate between 1 and 2. The simplest process is to multiply out experiences and isolate properties. Put a dark-colored gazelle in front of the lion, and then a light colored 747. Experiments to show other things might be more elaborate: for example, it was not known until quite recently that what the frog chased after was not a fly, but a moving object of a certain size. A frog in a room full of dead flies would starve to death. Most persons, now and forever, think that frogs eat flies, and that they eat moving flies only by per accidens (or, that it would even prefer a fly that was not moving). In fact, the reverse is true. Notice that this is the case even though frogs have, in fact. always eaten flies.

But if it is accidental that frogs eat flies, even while it happens that they have always sought them, there is an accidental cause that happens always or as a rule, and another kind of accidental cause that does not happen always or as a rule. Chance events are the second kind. Frogs don’t eat flies per se, but we would not say that they eat them by chance. Chance must be outside both what is per se (frog eats the moving) and what is accidental but occurring always or as a rule (frogs eat flies). Contrariwise, one of the main goals of science- in both the ancient and contemporary senses of the term- is to find a way to rule out both chance and the accidental but occurring always or as a rule. Teh former is frequently difficult to rule out, the latter is, in some cases, impossible to rule out.


  1. Tap said,

    March 30, 2010 at 1:55 pm

    what would you recommend as an introductory work, before someone dives right into Aristotles work?

  2. March 30, 2010 at 2:30 pm

    (be careful who you ask for advice. 🙂 Here’s my answer)


    And Euclid!

    The standard recs. are the best to start with: Apology, Phaedo, Meno, Gorgias, Republic Books 1+2, find one you like and read it a few times. If you’ve read them before, read one again. If you go on to specialize in Plato, translations will start to matter, but before that, it’s more important just to read whatever you have.

    You don’t need to read anything before Plato or Euclid, but you do need to know how to read them. Their books are like your script. Knowing how to read one is like knowing how to perform one. To read Plato and Euclid you have to do things. Read Plato’s argument and then summarize it as briefly as possible, using only terms he uses. Do not say what it means, just write down what Plato says, no matter how loony it might sound, or how much you might want to compare it to other things you’ve read, or use terms from other philosophers.

    Read Euclid’s Elements, at least book I and 3. read each prop, then close the book and do it yourself. Feel free to take a few months to do this.

    I know this isn’t exactly what you expected to hear. Most people would refer you to some book with a title like “Perspectives in Contemporary Aristotelian Logical Worldmaking: an integrated study” by D. W. Q. Mc Snodgrass. No No No! All those other books might tell you what Aristotle thought, but Plato and Euclid will teach you to think like Aristotle thinks. Without developing the second, you’ll never understand the first.

  3. Onus Probandi said,

    March 30, 2010 at 8:39 pm

    Dr. Chastek:

    Even when Science is able to get down to the bottom of things, where through vast explorations, be it in the molecular world or otherwise, and is able to ascertain a vast wealth of information and even, in some instances, a certain level of certainty as to some Cause or what not; there yet remains that unsettling question which, quite interestingly, revolves around that same ole dilemma not so unfamiliar to us.

    To explain, what follows is the intro to an article just recently read at a science spot I typically frequent due to the nature of my own work (and, I admit, my own fondness for science apart from The Faith):

    “Adaptive Complexity’s Michael White writes that the big questions in biology — such as what makes us human — are difficult to answer using molecular biology. He writes that scientists can associate genes with a process, but not at going from the molecular biology level back up to the organismal level. “In other words, we’re good finding causal links between traits and genes. And thanks to genomics, we know the molecular function of many of those genes. … We can then explain the molecular effects: mutating a gene at a particular point results in a protein that does x,” White writes. “This is where things tend to dead-end: on the smallest scale. The chain of explanation is never brought back to the initial trait that set off the research.””

    Here is the link to the article itself:

    Perhaps this is why some scientists are returning to this:

    The Resurrection Of Metaphysics?

    After having considered the notion once before:

    Does Science Make Metaphysics Obsolete?

  4. Tap said,

    April 1, 2010 at 5:51 pm

    Sorry for getting back late to you, and thanks for the suggestions!

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