The topic of free will is always an interesting topic. Some deny it exists, others see it as a necessary prerequisite to make moral choices, still others think the concept as a whole is nonsense. A lot of "-sms" tend to be flung around in discussions related to free will. Some of these include determinism, indeterminism, compatibilism, libertarianism etc. Any meaningful discussion of course relies on proper definitions or at least a proper agreement on definitions among the participants in a discussion. People have different views and definitions of the concept free will. The Internet Encyclopedia of Philosophy lists at least three models for the concept of "will" alone. These include: Faculties Model of the Will Hierarchical Model of the Will Reasons-Responsive View of the Will Stanford Encycolpedia of Philosophy defines free will as "a philosophical term of art for a particular sort of capacity of rational agents to choose a course of action from among various alternatives." In this seemingly simple definition there are terms which demand definitions as well. E.g. "capacity", "rational agent", "to choose", "action". We are faced with many definitional problems and questions before any discussion will appear fruitful. 1) Which model of the "will" is right? 2) Do all agree on the definitions? Do all even understamd the defitions of terms within a within specific definition? 3) Can empirical physical sciences prove or disprove free will or show which model of the will is right? How? 4) Can quantum mechanics contribute to the discussion? 5) Does a person's concept of "matter" play role in the discussion? 6) Can free will only be proven or disproven through the general sciences such as logic, philosophy and metaphysics? So let's look at a few definitions and see if we can get some sort of agreement among those who are willing to participate in this discussion. On the Definition of Free WillWhat does it mean to be free and what does it mean to have a will? There are various definitions and as always it is important to be clear about what you are talking about. So I'll be choosing the definitions I think are most appropriate to the current discussion. Free: Not determined by anything beyond its own nature or being. Will: The will is an intrinsic faculty or capacity of something that causes it to desire or have an appetite for something or be attracted to something. I'll try and make this more clear as we discuss examples. As you can see, the concept of free will has two parts, "free" and "will". Implicit in the definition is that one can have at least four types of "things"; 1) Things that are not free and do not have a will. 2) Things that are free without having a will. 3) Things that have a will and are not free. 4) Things that are free and have a will. One way of coming to understand the concept of free will is to first look at examples of each of the four things above, 1) Things that are not free and do not have a will. Take for example the falling piece of glass (see below). It does not appear to have a will, it's attraction to mass is as a result of the force of gravity AND its mass. It's mass cannot really be said to "desire" to be closer to other masses. It is also not free since it's attraction to other masses is determined by something beyond itself i.e. the force of gravity. So I would argue the example of a falling piece of glass constitutes something that is not free and does not have a will. 2) Things that are free without having a will. Perhaps the easiest and best example of something that is free is to look at quantum mechanics. The Stern-Gerlach experiment is a good example of quantum phenomena. Below is a crude representation explaining some of the phenomena (Here are some slides from MIT and here is a technical explanation for those interested. Here is also a nice link that let's you do the actual experiment). Please Register or Log in to view the hidden image! Detectors A and B detect Sz spin (spin pointing along the vertical axis z) Detectors C and D detect Sx spin (spin pointing along the horizontal axis x) At time zero (T0) an electron in a state with spin pointing along the vertical axis is prepared. One can say that if an electron with a spin Sz=+½ (spin pointing along the vertical axis) is prepared at T0 then; 1) Detectors A and B will always detect electrons with spin Sz=+½ at T0+a (a=infinity with no other interference) 2) Detectors C and D will always detect electrons with Sx=±½ at T1 (the first measurement). Sx is thus indeterminate before T1. 3) If at T1 Detector C measures Sx=-½ (after measurement) then Sx will be -½ at T1+a (a=infinity with no other interference) and Sz will be ±½ at T2. Sz is indeterminate before T2. Or stated differently: 1) An electron prepared in the initial state with Sz=+½ will have a determinate Sz value (+½) whenever it is measured if left undisturbed. 2) An electron prepared in the initial state with Sz=+½ will have an indeterminate Sx value (±½) before measurement. 3) An electron prepared in the initial state with Sz=+½ will have an indeterminate Sx value (±½) before measurement and a determinate Sx value after measurement. However, after the Sx measurement is made, the Sz value becomes indeterminate. From this one can argue that an electron prepared in the initial state with Sz=+½ is free to have either an Sx=+½ or Sx=-½ and this freedom is NOT determined by anything beyond itself. So I would argue the example of an electron with spin pointing along the vertical axis (Sz=+½) constitutes something that is free and does not have a will. 3) Things that have a will and are not free. I'd like to propose that the instinct of living things may satisfy something that is a will but is not free. Therefore, an instinct is a kind of will that is not free. Now things that have free will may have instincts, it does not mean that if you have instrincts you cannot have free will. Take an ant as an example. An ant has an intrinsic faculty or instinct to desire or have an appetite that causes it to be attracted to food. I think an argument can be made that it is not free. While an ant's instinct is intrinsic, it is determined by extrinsic factors such as the availability of food. 4) Things that are free and have a will. Imagine some sort of alien life form. It has an intrinsic faculty or capacity that causes it to be attracted to something or desire something or have an appetite for something. Let's say this capacity is free. This implies that this capacity or faculty is not determined by anything beyond itself. It follows then that this alien is free to follow its desire or not to follow its desire (or will if you want) and this freedom is NOT determined by anything beyond itself. Next, let's look at a few of the "-sms". The "-isms" "-isms" are usually big words that tend to make everyone feel stupid. What follows is just my attempt to make sense of all the "-sms" and other definitions nomrally associated with discussions surrounding free will. Check out these links for more info: Free Will (IEP) Free Will (wiki) Free Will (SEP) Foreknowledge and Free Will (IEP) Foreknowledge and Free Will (SEP) Causal Determinism (SEP) Determinism (wiki) Hard Determinism (wiki) Dilemma of determinism (wiki) Compatibilism (SEP) Incompatibilist (Nondeterministic) Theories of Free Wil (SEP) Determinism and the different main varietiesAfter reading the above I think I am comfortable with distinguishing between three varieties of determinism. Logical, causal and hard determinism. For the purposes of this discussion I will briefly define them as I understand it. Logical Determinism: Logical determinism is associated with propositions. A proposition such as "Married bachelor" is false now and is always false. The proposition that "X will happen at time Y" is true or false now and forever. Causal Determinism: Causal determinism is associated with causes. In a nutshell, every event is causally necessitated by antecedent events or to state it differently; the same causes acting in similar circumstances will always produce the same effect. Hard Determinism: In the context of this discussion I would characterise hard determinism as a combination of logical and causal determiniation and analogous to the epistemic determinism described here. Briefly, causal and logical determinism are both true and all causes and propositions are known. Indeterminism and the main different varietiesI will use the same classification scheme. Briefly: Logical Indeterminism: Logical indeterminism is associated with propositions. A proposition such as "Married bachelor" is false now and is always false. However, proposition about events are not always true or false, they are only true or alse at the event and not before it. In other words the proposition that "X will happen at time Y" is neither true nor false before time Y and true or false at time Y and forever after time Y. Causal indeterminism: Causal indeterminism is associated with causes. In a nutshell, every event is causally necessitated by antecedent events oor to state it differently; the same causes acting in similar circumstances will always produce the same effects (plural). Note the plural. In other words it may be the case that the same cause may produce different effects in an indeterminate manner. Hard Indeterminism: In the context of this discussion I would characterise hard indeterminism as a combination of logical and causal indeterminism. Briefly, causal and logical indeterminism are both true and all causes and propositions are known. However, as a result of the indeterministic nature of causality, it is logically impossible to know the effect of a particular cause that may produce more than one effect since the effect is caused in an indeterminate manner. Below is a summary (Scheme A). Please Register or Log in to view the hidden image! Scheme A Take the following example following the above scheme: A = Falling piece of glass B = Shattered glass on floor C = Fully in tact piece of glass on floor D = Chipped piece of glass on floor The proposition "the glass lies shattered on the floor at Time=1+x" is always true for Logical Determinism. The proposition "the glass lies shattered on the floor at Time=1+x" is indeterminate before Time=1+x and always true at and after Time=1+x for Logical Indeterminism. The falling piece of glass at Time=1 will always cause the shattered glass on the floor at Time=1+x for Causal Determinism. The falling piece of glass at Time=1 will always cause either the shattered glass on the floor or the fully in tact piece of glass on floor or the chipped piece of glass on floor at Time=1+x for Causal Indeterminism. The proposition "the glass lies shattered on the floor at Time=1+x" is always true AND the falling piece of glass at Time=1 will always cause the shattered glass on the floor at Time=1+x for Hard Determinism. The proposition "the glass lies shattered on the floor at Time=1+x" is indeterminate before Time=1+x and always true at and after Time=1+x AND the falling piece of glass at Time=1 will always cause either the shattered glass on the floor or the fully in tact piece of glass on floor or the chipped piece of glass on floor at Time=1+x for Hard Indeterminism. A few interesting questions appear from this classification. 1) Can Logical Determinism and Causal Indeterminism be simultaneously true? 2) Can Logical Indeterminism and Causal Determinism be simultaneously true? I'll leave this one for now, it is open for debate. What about acausality? Is it possible to have acausal determinism and acausal indeterminism? Perhaps, however, it would appear that it has to have the form of logical Determinism or Indeterminism. Note that in the above scheme logical determinism and logical indeterminism are opposite but it is not the case with causal determinism and causal indeterminism. Below is a summary. Scheme B. Please Register or Log in to view the hidden image! Scheme B Taking the above example: The proposition "the glass lies shattered on the floor at Time=1+x" is always true AND the falling piece of glass at Time=1 is in no way causally related to the shattered glass on the floor at Time=1+x for Logical Acausal Determinism. The proposition "the glass lies shattered on the floor at Time=1+x" is indeterminate before Time=1+x and always true at and after Time=1+x AND the falling piece of glass at Time=1 is in no way causally related to the shattered glass on the floor at Time=1+x forfor Logical Acausal Indeterminism. One thing I think that can be concluded from the above discussion is that the will is something that has a causal influence on something else and freedom is indeterminate. Whether freedom is causal or acausal is of course another thing that can be debated. Before we try and figure out whether something with free will can exist if any of the "-isms" are true, let's first tackle the issue of whether there is a difference between something that is random and something that is indeterminate and how this relates to freedom. Randomness vs Indeterminism There is no agreed definition of randomness, however, one can perhaps make sense of the concept as an absence of ALL order or ALL predictability. Suppose there is something that behaved in a way that could only be described as random smething that changes in a totally unpredictable manner. Let's take an electron with spin Sz=+½ as an example. One moment it is an electron with Sz=+½ around the nucleus of hydrogen in laboratory on earth, the next moment it is moving towards the sun and randomly changes to a proton of carbon and then inexplicably moves back, the next moment it is some gold nugget on its way towarsds Mars. Suppose you want to measure Sx, you could never in principle know whether it would suddenly change into a gold nugget or a proton or fly to the sun or Mars and back or just be Sx=+½ or Sx=-½ etc. One can say that such an electron would have freedom and this freedom is not determined by anything, not even itself. There is no part or property or nature of the electron that determines what it will change into. The freedom is purely random as it is not determined by what kind of thing the electron is. Contrast this with the freedom of things that are indeterminate. Let's take the electron with spin Sz=+½ again as an example. From experiments we know that Sx is indeterminate and that the electron is free to be either Sx=+½ or Sx=-½. upon measurement of Sx. We are able to predict that it will be either Sx=+½ or Sx=-½ even though it is indterminate before measurement. The freedom is determined by something that is part of the electron, some property of the electron. One can say that the electron has certain dispositions, there is order (either Sx=+½ or Sx=-½, not pure radmoness) in the freedom of an electron. The freedom is not random, it is merely indeterminate. So while randomness entails indeterminism, indeterminism does not entail randmoness. One can have indeterminism and order and one can have indeterminism and randomness. The obvious consequence is that Free Will can be ordered and free will can be random. But that is a debate for another day.