
Professor of Philosophy
Areas of Interest: Logic, Philosophy of Science, Epistemology
Humboldt State University
Ph.D. Michigan State UniversityWeb sites for:
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Essays in Philosophy |
Reductio Proofs as a Method |
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2013 Broadview Press) in Teaching Philosophy, March 2014.
2001 by MIT Press) in Essays in Philosophy, Vol. 8, No. 1, January 2007.
2004 by Harvard) in Essays in Philosophy, Vol. 5, No. 2, June 2004.
2000 by Oxford) in Mind, Vol. 111, No. 441, January 2002.
2001 by MIT Press) in Essays in Philosophy, Vol. 2, No. 2, June 2001.
1999 by Rowman & Littlefield.) in Ethics, Vol 110 No. 3, April 2000.
Consider the disjunctive sentence "We will go to the beach or the zoo." One way to interpret the meaning of this sentence is to say that the utterer means that "we will go either to the beach or the zoo but we won't go to both". This, then, would be the exclusive sense of the sentence. The inclusive sense would be something such as "we will go either to the beach or the zoo and maybe both". Inclusive disjunctions cannot be adequately translated into sentential (propositional, statement) logic, because of the word "maybe" in the sentence. 'Maybe' means "perhaps" or "it is possible that." There is no symbol in sentential logic for such words/phrases. Rather, we need a modal logic for that. This is the reason that, in sentential logic, we take disjunctions that are not specific in their inclusive/exclusive meaning to be inclusive. This plays out in a practical way when we consider the form of argument of the Stoics. The form of this argument is this:
Premise 1: We will go either to the beach or the zoo.
Premise 2: We will go to the beach
Conclusion: We will not go to the zoo.
The Stoics considered the first premise an exclusive disjunction. So, they saw this argument as valid. And, on this interpretation of the first premise, the argument is valid, because if the premises were true, the conclusion could not be false. However, if one interprets the first premise inclusively, then the argument is not valid; that is, even if the premises were true, the conclusion could well be false.
A very good "real life" example of the care that must be taken with interpreting disjunctions is when your insurance policy includes the following sentence: "This policy covers you when you are ill or unemployed." One must ask: Is this an inclusive or an exclusive 'or'. It will turn out that if the sentence is inclusive, then the policy statement needs to be rewritten so that the sentence says that the policy covers you if it should be the case that you are ill and unemployed. If, on the other hand, the policy statement is interpreted as an exclusive 'or,' then I would say that you should find another insurance company.
1. Working on a paper attempting to discover the correct way to translate inclusive disjunctions. My suspician is that inclusive disjunctions, where you leave the possibility open that both disjuncts are true (e.g., "This policy covers you when you are either ill or unemployed"), involve a modal operator. If so, then perfect translations of inclusive disjunctions are not possible in either sentential or predicate logic. Only a suitably nimble system of modal logic will capture the real meaning of these sorts of sentences.
2. Almost finished with a paper about the nature of deductive arguments. There seems to be some disagreement about just what consitutes a deductive argument, with some logicians arguing for an arguer-centered approach, with various forms. I think this is an indefensible approach. The arguer-centered approach would allow any argument to count as deductive. The other, perhaps more important, aspect of the paper is to define 'deductive argument' in such a way that we can give specific examples of invalid deductive arguments.
3. Working on a paper in modal logic attempting to show that using the "necessity elimination" rule can lead to a paradox (or possibly a contradiction). The necessity elimination rule is one that all logicians working in modal logic accept. It is, as C.I. Lewis puts it, that "What is necessary is true." Logicians refer to this idea in multiple ways: as an axiom in modal logic, as a theorem, as primitive in the system, and so on. I have not found one serious treatment of modal logic that does not cite this inference/axiom... If it should prove paradoxical...
4. Still working on the paper attempting to answer the following question: What are the implications for the meaning of '=', and the concept of logical identity, of not being able to show that '(x)x=x' is a logical truth? My intuition at present is that the answer turns on a double use of the identity sign; that is, it is used as a predicate in some systems (e.g., where 'Iwa' might be translated as "Woody Allen is identical with Alan Konigsburg") and as a sign in others (e.g. where 'w' = 'Woody Allen' and 'a' = 'Alan Konigsburg' yields 'w = a'). What difference this makes is part of what I'm investigating.
Chair of the Department of Philosophy, Member of School of Business Personnel Committee, College of Arts, Humanities & Social Sciences Subcommittee on Curriculum, Member of the Department of Native American Studies Search Committee, University Ombudsman, Chair of the Academic Senate, Member and Chair of Educational Policies Committee, Member of Dean Search Committee in Arts & Humanities, Chair of Student Grievance Committee, Chair of the Religious Studies Department, Chair of the Department of Music, Chair of the Department of Theatre, Film & Dance, Chair of the Department of History, member of the Faculty Affairs Committee, member of the College of Arts, Humanities and Social Sciences Budget Committee, member of the College of Arts, Humanities & Social Sciences Personnel Committee, member of the University Senate Academic Policies Committee.
Surfing, playing music (guitars), listening to rock 'n roll (especially Neil Young and a group listed below), racquetball, woodworking, summer slow-pitch softball, fishing.


Below: The first was taken recently at our house in Arcata; the second is one in a series of about 5 and was taken in 1966, in Vista, California, by a friend of mine, Gary Privetts, who had an assignment in his photo class to get shots which show extreme presence and absence of light (original is black & white); the third was taken in the early 50's sometime, complete with cowlicks (I don't think I'm that happy anymore). Right below that is a picture of Caleb, my grandson. Flawless. A few other family-type pictures are here.

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Buy the kid a decent bat, wouldya?