Maverick Philosopher

Now, if in this process I will repeat certain things that other commentators have said without giving them due credit, I apologize in advance. Due to time pressure I am unable to trace points I make to particular contributors. However, I do wish to mention Malcolm who, in my opinion, quite justifiably argued that we simply cannot rely only on intuitive considerations to support a demarcation between potentiality and possibility and, thus, between the unfertilized egg and the fetus. A general criterion must be provided, he maintained and I agree. So without further ado, here it is.

1) What are the intuitions that support making a sharp distinction between an unfertilized egg and a fetus so that we can say of the latter that it has the potential to develop into a mature human, whereas it is merely possible for the former to turn into a mature human, but has no such potential?

1.1) The Conceptus’ Case: The internal constitution of a conceptus or a fetus is such that given a suitable environment it will interact with certain external conditions in such a way that it will eventually grow into a mature human being. It is important to emphasize that while these external conditions are necessary in order to enable these natural processes to take place, they are contributing factors that enable these processes to take place regarding one and the same thing. The idea that we are dealing here with one and the same entity can be traced to the notion that this entity can be individuated by its internal constitution; that the changes this entity is undergoing are principally driven by its internal constitution and the role of the external circumstances is to provide an enabling environment for such changes to take place in the normal course of things; and that there is a lawlike-link between each stage in the development of the entity, from the beginning of its existence until it perishes. So to apply this to the case of the fetus: once a conceptus is formed, it features a unique internal constitution which can be used to individuate it. The internal constitution of a conceptus is principally responsible for the changes (cell division) it is undergoing. And each stage in the progression of such change is linked in a lawlike fashion to the previous stages so that a lawlike continuity is present among stages. As a result, the whole chain of stages can be lumped together as the development of one and the same individual entity. Hence, the conceptus, fetus, newborn child, adolescent, adult, elderly, are all stages of one and the same entity. It is in this sense that the proponents of the potentiality argument feel that it makes sense to attribute certain potentials to the conceptus, but not to an unfertilized egg. Why?

1.2) The Unfertilized egg case: What conditions must be realized in order for an unfertilized egg to turn into a mature human? Well, in order for an unfertilized egg to turn into a mature human it must interact with a completely different thing, namely a sperm, which process will convert the unfertilized egg into something else, namely, a fertilized egg. So we have here two things, an unfertilized egg and a sperm, each with different internal constitutions, such that given suitable conditions, their interaction yields a third thing; namely, a fertilized egg, the latter of which is distinct in constitution from both previous things.

1.3) The distinction I have tried to articulate in (1.1) and (1.2) is the source of the intuition that in the case of the fertilized egg it has the potential to become a mature human because while the external conditions are necessary for it to so become, they are necessary in a way of contributing to a suitable environment for a natural process to take place of the very same entity. Whereas in order for an unfertilized egg to become a mature human it must undergo an identity change by interacting with a different entity, a sperm, and this identity-altering interaction creates a new entity, different from both. Hence, while it is certainly possible for an unfertilized egg to turn into a mature human because it is possible for it to undergo an identity change by interacting with a sperm in the normal course of things, it does not have the potential to do so, because it is no longer the very same thing before and after such an interaction.

1.4) In order to sharpen the above intuitions let us consider Bill’s acorn/oak example and contrast it with two other cases the yeast/dough-case and the sand-heap case.

Example 1-the acorn/oak case:

In this case the acorn when provided with the suitable enabling conditions will grow into an oak. How does that happen? Well, the internal constitution of an acorn is such that when provided with suitable external conditions (water, sun, temperature, etc.,) it will interact with them in a manner that certain changes in the acorn take place. These changes are driven by the internal constitution of the acorn in the sense that they are predetermined (coded into the acorn’s constitution) conditional upon the presence of suitable enabling external conditions. Moreover, these changes involve a continuous process without there being any intermediary stages involving the emergence of an entity that features a completely different internal constitution. Thus, we can appropriately say not only that it is possible for the acorn to become an oak but also that it has the potential to become an oak.

Example 2-the yeast/dough/bread case:

In this case the yeast has an internal constitution such that when combined with other ingredients with their own internal constitution the result is stuff we call ‘dough’ which features its own internal constitution different from the internal constitution of the ingredients that go into making the dough. And the internal constitution of the dough affords it with certain unique properties that none of its ingredients in isolation from the others have such that given certain external conditions it, for example, will rise and become bread. Thus, the difference between the dough and the bread depends upon suitable external conditions that enable the internal constitution of the dough to trigger changes that turn the dough into bread. There is a certain (lawlike or natural) continuity between the dough and the bread such that the dough is the initial stage of this continuous process and without the introduction of a new entity with a different internal constitution this process culminates with the dough turning into bread.

The same cannot be said about a process that begins with yeast (or flour) and ends with bread. For a process that begins with yeast and ends with bread involves an intermediate stage. This intermediary stage is the creation of dough that features a completely different internal constitution than the one featured by yeast. And the presence of this intermediary stage that features the emergence of a substance with a different internal constitution creates a “wall of separation” between yeast and bread, a wall that breaks the natural continuity between yeast and bread and creates two natural processes: one process is the creation of dough that involves yeast as one of the ingredients; and the other is the process of the creation of bread from dough by supplying suitable external conditions. Therefore, while it is appropriate to say that it is possible for yeast to become bread, it is not equally appropriate to say that the yeast has the potential to become bread.

So this example highlights the idea that potentiality, unlike possibility, requires a certain natural continuity between the entity said to have the potential and its future self that manifests the potential in question.

Example 3-the sand-heap/mountain case:

It is certainly possible that a one foot sand heap shall turn into an impressive mountain provided we give its surrounding environment enough time and certain conditions take place such that …. But it would be a huge stretch to point to this one foot sand heap and say: “Hey, you know that this sand heap has the potential to become an impressive mountain!” Why is that? Because there is a very strong sense in which the resulting mountain is linked to the sand heap merely through the action of external circumstances. There is nothing about the internal constitution of the sand heap itself that would in any way project the possibility that it should become a mountain. The full responsibility for the possibility of this sand heap turning into a mountain rests upon external conditions. Thus the resulting mountain is a totally different entity from the sand heap. If one insists that a causal connection between the sand heap and the mountain nonetheless exists, then one would put it as follows: the sand heap undergone a radical identity change and turned into a mountain, due to such and such external circumstances. The only credit that the sand heap deserves here, perhaps, is that it can be described as being the initial-causal starting point for a process culminating with a mountain. It makes no other contribution to the process or resulting outcome. In such a case we will say that the sand heap no longer exists, and that a mountain took its place or that it is possible that in place of this sand-heap a mountain should emerge, given suitable external processes. But, it certainly makes no sense to talk as if the sand-heap features the potential to become a mountain given enough time etc.

2) Can we convert the intuitions behind these examples into a demarcation criterion that distinguishes potentiality from possibility?

2.1) Well, the differences we have found between the examples of the yeast/dough/bread and sand-heap/mountain point towards such a criterion. It is inappropriate to use the term potential unless there is a certain natural continuity between the entity to which a potential is attributed and one of its future stages which realizes such a potential. I shall call any process satisfying this condition a natural kind continuum. So the acorn/oak case is a natural-kind-continuum and so is the process beginning with dough and ending with bread. But the process beginning with yeast and ending with bread is not a natural-kind-continuum because it involves a sub-process that is itself a natural-kind-continuum (which begins with a substance with an internal constitution that is different than yeast and ends with bread).

Hypothesis I: Any process beginning with a natural kind A and culminating with a natural kind B which contains as a sub-process that is itself a natural-kind-continuum is itself not a natural-kind-continuum.

Hypothesis II: The term ‘potential’ properly applies only to an entity that is the beginning point of a natural-kind-continuum.

Hypothesis III: The term ‘potential’ is inapplicable to any entity that constitutes the initial stage of a process culminating with a certain result unless the internal constitution of the entity in question is involved essentially and triggers the process to take place.

2.2) Hypothesis I and II rule out that the case that an unfertilized egg has the potential to become a mature human being with suitable right-making properties. Hypothesis III rules out any other cases in which the internal constitution of the entity in question plays no role in the making of a property under consideration to be a potential of the said entity.

2.3) I think that the above criteria capture the intuitions of those who argue that there is a sharp difference between potentiality and possibility. Now I am certain that this proposal is vulnerable to many objections and it may not be as precise and clear as I would like it to be. Nonetheless, I hope that it represents a useful beginning for a discussion of this topic.

Education cannot be a business (or run as such) because any business involves an expectation by the investor of a timely return on his investment. Note my emphasis on 'timely'. The return on investment (whatever that may be) in the realm of education, however, cannot be measured by any reasonable time-frame and the return on investment is distributed in a manner that would not directly and immediately benefit the investor. So the attempt to run educational institutions like businesses erodes their educational goals. I do not have an alternative to the current state of affairs, but I know it is not working.

Higher education is in the same boat. The trend to run colleges and universities as businesses gradually eroded their principal mandate to educate and shifted the focus to administering rather than educating. Professional philosophy gradually died in this atmosphere. By 'professional philosophy' I mean what it really means: i.e., 'the love of wisdom and its inquiry is the profession of the philosopher's soul.' Such attitude cannot express itself in a department dedicated to maintaining itself by the level of enrollments in courses, by the number of publications of its faculty, etc.

One result: Empty halls in some departments still echo passionate conversations from the past; yet faculty members cannot hear them for they are hiding in their offices busy charting their next step in the ladder of Assistant to Associate to Full, to etc.

I have heard Sidney's* voice in the empty halls of one department; his tortured passion to dig deeper and challenge any stand come what may; he was a professional philosopher, par excellence. And, yet he once told us, his graduate students: I would never have succeeded in getting a position if I had to do what you guys will have to do to get a job.

I miss that.
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*The reference is to Sidney Morgenbesser (1921-2004). See Sidewalk Socrates, TimesOnline obituary, and New York Times obituary.

Question: What is the interpretative problem in the Book of Job?

The Book of Job can be divided into three scenes:

Scene (A): The opening scene. God and one of the angels, whom I shall call ‘The Skeptic’, engage in a debate about human nature. God proposes the thesis that humans are good by nature and circumstances turn them toward evil. The skeptic maintains that human beings are bad by nature and circumstances turn them toward good. God illustrates his position by singling out the righteousness of his “loyal servant” Job. The skeptic is not impressed by this example. He points out that Job exemplifies one half of his own position because Job’s righteousness can be attributed to the favorable circumstances with which God endowed Job. The two agree to perform the following “crucial experiment”: God gives permission to The Skeptic to change Job’s good fortunes by taking away from him all “the goodies” except his life. The point of this crucial experiment is to see whether Job will turn evil due to the radical change in his fortunes, or remain righteous.

Scene (B): The middle scene. The Skeptic proceeds with the crucial experiment and Job’s fortunes change. Job asks: Why is this happening to me? The book then describes a lengthy and involved dispute between Job and some friends about the proper answer to this question. The dispute turns on the following fundamental issue: Is Job's terrible fortune a sign that he has sinned against God or not? The friends argue that it must be and, therefore, Job needs to ask God’s forgiveness. Job argues that it cannot be because he knows that he did not sin against God. The two sides never come to an agreement.

Scene (C): The end Scene: God appears before Job. The reader is now on the edge of his seat. Here comes the final authority. Surely, God will reveal to Job the truth about his predicament and to us all the solution to the problem of evil. Instead God goes into a “macho” speech about how Job was not present when God created the world, the mountains, the rivers, etc. At the end of this scene Job behaves as if God’s speech removed his puzzlement and walks away with a clear sense of relief and understanding.

Question: What did God tell Job in this speech? What did Job understand from God’s speech?

2) The Orthodox Solution: In the speech God tells Job that since Job was not present when God created the world, mountains, rivers, etc., Job is not in a position to understand the purpose behind the design of the world. Therefore, Job should not try to understand his own turn of fortune because it is an inevitable result of a purpose that is incomprehensible to Job. Thus, the orthodox interpretation offers the following moral of the story of Job: God’s moral fabric of the world is incomprehensible to human beings; the problem of evil is part of this moral design; therefore, the problem of evil is inscrutable to human beings.

3) The orthodox solution cannot be correct: Do you, the reader, have an answer to the question why Job’s fortunes turned so terribly? Sure you do! The opening scene of the Book tells you quite clearly and explicitly why Job’s fortunes turned to the worst. The Book of Job does not hide the causal antecedents of Job’s turn of fortune. They are there, black on white, for all to read.

Yet God does not tell Job what you the reader already knows. Why? Why does God not tell Job, his loyal servant, the truth about his dispute with the skeptic, the crucial experiment, the impact of this experiment on Job’s turn of fortunes? Why is God not honest with Job? If you the reader can understand the opening scene, so could Job! Why does God go into a speech about matters that appear to be totally irrelevant to the true causal antecedents of Job’s subsequent predicament?

In my opinion this line of questioning appears to undermine the orthodox interpretation of the Book. But, then, what is the correct interpretation of the End Scene? What did God tell Job in that strange speech? What did Job understand from the speech about his own predicament and, by implication, about the problem of evil? What should we take away from the Book of Job?

Briefly (and with some of my own modifications) this is what Plantinga proposes. Let Ω be an arbitrary set of propositions. Ω is said to be formally inconsistent just in case its deductive closure¹ contains a contradictory pair of propositions. Now, there are cases where we know that a given set of propositions is not co-possible, not all of them can be true, but the deductive closure of these propositions does not contain a contradictory pair of propositions. We can convert this set of propositions into a formally inconsistent set by adding a new proposition as an auxiliary premise. However, in order to carry out such a conversion, the auxiliary premise(s) added must be a necessary truth. Here is an example²:

Example I:

1) This book is red.
2) This book is not colored.

Now, we can immediately discern that (1) and (2) cannot both be true; yet they do not entail a contradiction. However, suppose we add the following premise:

3) Everything that is red is colored.

Clearly (1)-(3) are formally inconsistent. But notice that (3) is a necessary (analytical, if you will) truth.

Now several commentators on the logical argument from evil claim that all cases of implicit inconsistency arguments require that the converting [auxiliary] premises must be necessary truths. And while our intuitive reaction to cases such as Example I conforms to this claim, none of them (to my knowledge) offer a principled argument why this is so. I would like to raise two questions to begin the discussion on this topic:

(A) Is it true that in all cases of implicit inconsistency arguments the converting premises added must be necessary truths?

(B) If so, which distinctive features of implicit inconsistency arguments account for this requirement? ____________________________________
¹The deductive closure of a set of propositions is the set of all its deductive consequences.

²This example is inspired by Nelson Pike in his paper "Hume on Evil."

Question: What do you think about this argument? Does it make sense? My view: The argument commits a version of the Naturalistic fallacy; therefore, it is not sound. However, let others express their view and we can discuss them.

II. The Origins of OSD: OSD originates from a traditional interpretation of the Adam and Eve story in Genesis. Now, there is a difficulty familiar within theology with the traditional interpretation. Here is the problem in a nutshell:

1. Just punishment presupposes moral responsibility.
2. Moral responsibility presupposes the knowledge to distinguish (moral) right from wrong.
3. God will never punish anyone unjustly.
4. God ordered Adam and Eve not to eat from the tree of knowledge of right and wrong.
5. Adam and Eve ate from the tree and, thus disobeyed God.
6. Prior to eating from the said tree Adam and Eve did not have the knowledge to distinguish between right and wrong.
7. Therefore, Adam and Even were not morally responsible for their action of eating from the tree.
8. Therefore, they cannot be justly punished for this act.
9. Therefore, God did not punish them for this act.
10. But the traditional interpretation of the Adam and Eve story maintains that they were punished for this act.

Question: What do people think about this problem? My View : I think that this problem totally undermines the traditional interpretation to the extent that the OSD cannot be salvaged. But, there is a non-conventional solution to this problem that explores interesting terrain.

The first thing to note is that the enkratic man is not a virtuous man. Enkrateia is superior to akrasia and to vice, but inferior to arete. Virtue, Aristotle says several times in the NE, requires right action and right emotion. The virtuous man not only does what is right but he desires what is right and feels the right way about doing what is right. Since right desire is impossible without right belief, the virtuous man must not merely behave correctly, he must believe correctly (in order to experience the proper desires and emotions).

Virtue, then, on the Aristotelian model is impossible without a firm and reliable control of one’s beliefs.

The Stoics wonder how a man can believe x is good and desire x, yet decline to pursue it. Epictetus says at several places that human psychology is such that we will pursue what we believe is good. So no enkrateia on the Stoic model, and an absolute imperative to control our beliefs if we are to act right. The Stoics assert that belief is something that is in our control because it is subject to prohairesis. We can deliberate about and choose what we believe, at least in regard to those beliefs pertain to what is good and how we should act. The virtuous man comes to believe that no externals are truly good for us, only choosing virtue for its own sake is truly good, etc.

On the Stoic model, then, all our beliefs concerned with action are subject to prohairesis, and since desire and action inevitably follow belief, virtue is essentially right choice. Once again, if there is no firm and reliable control of one’s beliefs, there is no chance of virtue.

Something to think about. It is always amusing to hear contemporary cognitive therapists rehearsing these same basic points as they were new discoveries: "your actions are determined by your emotions which are created by your beliefs. To feel good and to act well, you must control your beliefs."

We must distinguish between the semantic content of a sentence, and its semantic force. (A) We can take any indicative sentence such as 'snow is white' and put the operator 'that' in front of it, to construct a noun phrase such as 'that snow is white'. This noun phrase denotes the 'semantic content' of the sentence. (B) We can express or assert this content either by removing the 'that' to yield the original sentence, or by adding 'is true' to give 'that snow is white is true' (or, 'that snow is white is a fact' or 'it is true that snow is white').

Note that adding 'is true' to the that-clause has an identical effect to removing the 'that' operator. I.e. what 'that' takes away, 'is true' gives back. (Every sentence, in effect, asserts its truth).

I claim that the semantic content C of a sentence is not a truth-bearer: truth is not a property that we assert of the content. Despite the grammar, 'C is true' is not of subject-predicate form, and thus 'true' not a genuine adjective that qualifies the subject (the sentence-content C) in some way.

For suppose per impossibile, that 'C is true' is of subject-predicate form. Then we would still have to assert that the truth-bearer C had the property of being true. I.e. the fundamental distinction between assertoric force and content would still have to apply. And we should still have to specify the content of the truth ascription by the that-clause C* = 'that C has the property of being true', and we should still have to assert that content either by subtracting 'that' or by adding 'is true'. But then this assertion would have the form 'C* is true' and thus we have not, contrary to hypothesis, specified the content in such a way that it already contained the ascription of truth.

In summary

(1) There is a fundamental distinction between assertoric force and content that we cannot do without, i.e. we cannot reduce assertoric force to some kind of sentential content.

(2) If truth were a property of a truth-bearer, the semantic contribution of 'true' would lie not on the side of assertoric force, but on the side of sentential content.

(3) But the semantic contribution of 'true' lies on the side of assertoric force.

(4) Ergo, the content of a sentence is not a truth-bearer, as defined. We assert the content of a sentence by adding the verb 'is true' to the content-specifying noun phrase. But that is not the same as asserting some property of the referent of the content-specifying noun phrase.

2. In Sec. 16 of the Discourse, Leibniz claims that miracles "are always in conformity with the universal law of the general order, even though they may be above [au dessus] the subordinate maxims." But what does it mean to be "above" a maxim? Is that which is above a maxim an exception to it? Apparently so, because elsewhere Leibniz characterizes miracles as, in effect, exceptions to the laws of nature. In some remarks on a letter from Antoine Arnauld, for instance, Leibniz writes that the divine resolves "have established this general and unchangeable order to which everything conforms without even excepting miracles, which are doubtless conformable to the principal designs of God, although the particular regulations which are called the laws of nature are not always observed." And in a letter to Arnauld written just a couple of months later, he comments: "Everything belongs to an order, even miracles, though they may be contrary [contraires] to certain subordinate maxims or laws of nature." From this it is clear that Leibniz does at least nominally view miracles as exceptions to laws of nature, even though they are not exceptions to the ultimate law governing the universe, i.e., the general order, which, being infinitely complex, is beyond our comprehension.

3. Since the general order of the universe cannot be violated, but the laws of nature can, it would appear that on Leibniz's view laws of nature are at best only partially in conformity with the general order, that is, with the way the universe actually behaves. But this is a puzzling thing to hold, insofar as it implies that laws of nature aren't really laws after all. (It implies this because, as you've heard, laws of nature are by nature exceptionless.)

4. Perhaps what Leibniz had in mind, or at least should have said, is this. Nothing that we call a law of nature -- nothing simple enough for our finite intellects to grasp -- is ever truly a law of nature. But the maxims that we accept at any given time, taken together, constitute the closest approximation to the general order available to us at that time. Thus if one of these maxims or "laws" of nature turns out to admit of some exception, we can conclude that the maxim isn't really a law of nature, since the existence of an exception entails that it isn't in conformity with the universal law of the general order. Still, it remains the closest thing we have to a genuine law of nature, and so we continue to think of it as a law until something better comes along, even though it isn't truly a law.

5. Leibniz's view of miracles is therefore hard to categorize. At least nominally, he accepts the traditional construal of miracles as violations of laws of nature. However, he also holds that miracles are never violations of the universal law, and so if a miracle ever violates some subordinate maxim, it follows that the maxim in question isn't in accordance with the universal law and therefore, it would seem, isn't really a law of nature. So viewed in another way, Leibniz appears to be promoting an epistemic conception of miracles. As he sees it, miracles only seem to be violations of the general order of the universe because of our inability to grasp that infinitely complex order. If per impossibile we could grasp the universal law, as God does, we would see that any miracles that have occurred were perfectly in accordance with that law and were determined to happen from the beginning. But since we are essentially incapable of ever grasping that law, there will always turn out to be exceptions to the maxims that we are capable of grasping. All things considered, this second way of viewing the matter seems to me to be closer to the truth. Like Spinoza and Kant, Leibniz appears to favor what essentially amounts to an epistemic conception of miracles.

1. According to traditional logic the two types of universal proposition (affirmative 'Every S is P' and negative 'no S is P') are contrary: they cannot both be true. Hence, their two subcontrary propositions 'some S is P' and 'some S is not P', which are by definition the negations of the 'contrary' propositions, cannot both be *false*.

2. But if each of the subcontrary propositions has 'existential import', i.e. implies the existence of the subject, S, it follows that the subject term cannot be empty, i.e. the subject exists.

3. All or most traditional logicians recognised that there were empty terms (e.g. 'goat-stag', 'chimera')

4. This flaw is pretty obvious and no such obvious flaw in a system evades scrutiny over a long period (in this case, over 20 centuries).

Clearly, one of these propositions must be false. Parsons argues that it is (2). Traditional logicians, he says, did not think that the O proposition 'some S is not P' has existential import. It does not imply the existence of any S's. It simply is the strict negation of 'every S is P'. Thus there is no obvious flaw in the system.

I reply as follows. First, traditional logic developed in Latin, and the Latin form of the O proposition from Boethius was 'quoddam S est not P', i.e. 'a certain S is not P'. The word 'quoddam' (neuter, 'quidam' masculine) is strongly existential. It means not just 'someone' or 'something', but indicates that the speaker knows the identity of the object in question, but is not divulging it. 'Someone in particular', 'a certain someone' &c.

Given that traditional logicians did think the subcontraries have 'existential import', how do we resolve the apparent contradiction? Answer: traditional logicians had a different sense of 'empty' than modern logicians. They thought that 'some S is not P' is existential in the sense that it implies something is an S that is not P. Thus there are no empty terms, in this sense. But they thought that some things (chimeras, goat-stags) do not exist in reality. Thus 1-4 are only inconsistent if we read 'empty' in (3) in the same sense as it is used in (2). If we read it in (3) as meaning 'has a subject that does not exist in reality', and in (2) as 'has a subject', there is no contradiction.

One of the best bits of evidence they thought this is that scholastic logicians tried to construct ontological arguments. If 'every perfect being is perfect' implies 'some being is perfect', and if 'some being is perfect' is existential, then the existence of God is a logical truth. So why did no traditional logician prove the existence of a perfect being in this way? Because 'some being is perfect' is not existential. It does imply 'some perfect being exists in reality'. (I owe this thought to Morris and Laserowitz, 1948).

Traditional logic … ignores the question of existence or non-existence, because it inquires only how things are thought.… Consequently there is implication between Every sea serpent is bearded and Some sea serpent is bearded, in spite of the fact that there are no sea serpents whatever. And its rule comes to this: if you think every sea serpent is bearded, you must think some are. (Wade)

Thus Parson's argument is anachronistic. Given the Brentano-Venn interpretation of particular proposition (i.e. that some A is B logically implies Some AB exists), Parson's argument is sound. But that interpretation was one of the most keenly fought battles in logic, begun in the 1850's, and not conceded by the majority until the 1950's – a real Hundred Years' War! If we do not accept that interpretation – and the evidence is that few traditional logicians accepted it – then it is perfectly consistent to hold (1) that there are empty subject terms, in the sense that the subject does not exist in reality (2) that there are no empty subject terms, because they all denote a 'something' (3) that subcontraries imply the existence of a 'something', though not necessarily an existing something.

I am neutral about whether the traditional interpretation of non-existential character of particular propositions is correct. But I would end by noting that

Not all characters in War and Peace were real historical characters

clearly implies

Some characters in War and Peace were not real historical characters

despite the fact that names like 'Natasha Rostov' are empty. Indeed, it is the emptiness (in one sense) of such names, that makes the implication valid.

the opinion concerning colors, sounds, tastes, smells, heat and cold; which it asserts to be nothing but impressions in the mind, derived from the operation of external objects, and without any resemblance to the qualities of the objects. (Treatise of Human Nature, I, iv, 4)

And even today one hears scientists and philosophers say similar things about color. For instance, Rolf G. Kuehni writes in his book Color: Essence and Logic:

Colors, as mentioned before, are not real, and the world in front of us is not colored. Our brain creates the sensations of colors, most often from certain quantities and qualities of electromagnetic radiation which strike our sensory organ.

Proponents of this view of color have come to be called projectivists, because they believe colors are properties not of external, physical objects, but of things internal to us, such as sensations, sense data, visual fields, or the like; and that when we sense things, we project these properties onto external objects, so that colors appear to be properties of external things when in fact they qualify only these internal things. Among recent philosophers, Frank Jackson, Paul Boghossian, and David Velleman have all endorsed this sort of view. Here is how Boghossian and Velleman characterize their position in their article "Colour as a Secondary Quality" (Mind 98 (1989), pp. 81-103; reprinted in Byrne and Hilbert, eds., Readings on Color, v. 1: The Philosophy of Color (MIT Press, 2001)):

We have argued ... that intrinsic colour properties of the visual field are the properties that objects are seen as having when they look coloured. We have thus arrived at the traditional projectivist account of colour experience. The projection posited by this account has the result that the intentional content of visual experience represents external objects as possessing colour qualities that belong, in fact, only to regions of the visual field. By 'guilding or staining all natural objects with the colours borrowed from internal sentiment', as Hume put it, the mind 'raises in a manner a new creation'. (94-95)

Boghossian and Velleman go on to claim that their projectivist view is "potentially neutral on the metaphysics of mind" insofar as it is consistent with both materialist and non-materialist accounts of what they are calling the "visual field." Though this seems strictly-speaking correct, I would argue that a materialist account of visual fields (or sensations, sense data, etc.) actually undercuts one of the primary motivations for being a projectivist in the first place. And if that's right, then unless there's some other motivation for being a projectivist, it follows that materialism and projectivism can't coexist comfortably; for the committed materialist would have no reason to accept projectivism, and the committed projectivist would have reason to reject materialism. Let me explain.

The motivation, as I understand it, is this. We would like it to be the case that physics gives us a comprehensive account of ordinary physical objects and their qualities. But colors are not among the fundamental properties recognized by physics, nor can they be reduced to such properties. Thus, if all the properties of ordinary physical objects are physical properties in this sense, and if colors are not physical properties in this sense, then colors must not be among the properties of bodies. But since colors are properties of something, they must be properties of something in the mind, which properties we then project onto the external objects we perceive.

Now the problem here is straightforward enough. If the projectivist is a materialist, he presumably believes that these things in the mind (sensations, sense data, regions of the visual field, or whatever) are themselves physical things, much like the ordinary physical objects that appear colored. But if colors are properties of these mental/physical things, and yet aren’t themselves physical properties, then it follows that there are physical things with non-physical properties. This means that physics cannot give a comprehensive account of these sensations or regions of the visual field. But if physics cannot give a complete account of these physical things, then why should we expect it to be able to give a complete account of ordinary physical things like racquetballs and blades of grass?

So to sum up, for the materialist a main attraction of projectivism is that it accommodates the thought that physics can give a comprehensive account of physical objects and their properties. But according to the materialist-projectivist, colors are really properties of certain physical things, specifically mental items. So if these properties are non-physical, then the thought about the comprehensiveness of physics must be rejected. On the other hand, if colors are physical properties, then there was never any reason to relocate them from external objects to the mind in the first place. So materialism undercuts this motivation for projectivism about color.

The upshot of this, to repeat, is that materialism and projectivism aren't a good fit for one another, despite the fact that a number of contemporary philosophers seem to favor both views.