Philosophy 309: Logic, Language, and Thought
Professor: Craig DeLancey
Office: CC 212 A
This class takes as its themes three questions:
- How do we come to know necessary truths through reason alone?
- Are there any limits to what we can know through reason alone?
- What does our study of reason tell us about the mind?
This class serves also an introduction to the relationship between
issues in the philosophy of logic, the philosophy of language, and the
philosophy of mind, focussing upon the historical quest for a
logically perfect language that would formalize reasoning. The course
does not teach logic, but rather reviews in a general way important
insights on a number of issues. These include: the dream of a
logically perfect language, the nature of paradox, the nature and
limits of computers, the nature and limits of mathematical and
algorithmic reason, and the difference between determinism and
predictability. The course should be of interest to majors in
philosophy, psychology, cognitive science, or to anyone interested in
questions about mind and meaning.
PHL111 or equivalent course work in logic, math, or computer science
are required for this course; however, I'm happy to waive this
requirement if you have sufficient skill in math and logic. The way
to tell whether this is so is to review the lectures and see if you
are comfortable with them. If not, then it would be best not to take
If you have a disabling condition which may interfere with your
ability to successfully complete this course, please contact the
Disability Services Office.
There will be extensive notes available on-line, via the course web
site. I will also provide you links to many readings that are available
on the web and on academic sites. For help, but not required, are
the following books:
Godel: A Life Of Logic, The Mind, And Mathematics, by John
L. Casti, Werner DePauli
Also available for free, and hopefully helpful to you if you need to
review any logic, will be:
Logicomix, by Apostolos Doxiadis and Christos Papadimitriou
DeLancey, A Concise Introduction to Logic.
This book can perhaps help you review logic and some of our proofs.
I'm also struggling to locate a decent turing machine program.
Assignments and exams
Your grade will be based upon performance on two exams and several
projects (we'll have 2-4 group projects) and homeworks (I'll aim for a
homework every week or so). The exams will cover the material discussed
in class. The projects will ask you to apply the material we learn in
The grade will be determined in the following way:
Homeworks: 60% (about a third of this will be projects)
I accept no homeworks by email unless specifically so stated.
Exams: 40% (20% each)
Projects will often be reviewed in the class period where they are
due. For this reason, late homeworks will not be accepted for
Note the exams or assignments may count more as the class progresses.
This means that you will always have the opportunity to catch up in
If you miss an exam and have an excused absence for the day you miss
the exam, you may make it up, by special appointment with me, when you
are able to come back to class. It is your responsibility to arrange
any make-up exams as soon as you know you are going to miss the
exam. Otherwise you may lose the opportunity to take the test, since I
cannot give make-up exams after the class has gone over the
Here is how you secure an excused absence: Only prior notification
with credibly documented or easily verifiable reasons (e.g., medical
visits to Mary Walker, documented participation in official sporting
events, etc.) will result in excused absences. You must notify in
writing, call, or email me prior to your absence from class. Or you
must notify the Philosophy Dept. secretary, Pat Meleski, before you
are going to be absent, via email at firstname.lastname@example.org, or by phone
at x2249. However, you must make sure she knows your name, the number
of the course, the date, and your easily verifiable reason, along with
a request to forward the information to me. It is better to give your
information to me, except when you are unable to communicate with my
phone or email for some reason.
Please hold onto all of your assignments and exams. Sometime before
the end of the semester I will ask you to review the grades that I
have recorded to make sure that I have not made any mistakes.
Any cheating will receive a zero grade, and will be reported to the
College Policy on Intellectual Integrity
Intellectual integrity on the part of all students is basic to
individual growth and development through college course work. When
academic dishonesty occurs, the teaching/learning climate is seriously
undermined and student growth and development are impeded. For these
reasons, any form of intellectual dishonesty is a serious concern and
is therefore prohibited.
The full intellectual integrity policy can be found at
By the end of this course, the things you will be expected to have
learned will include:
- Galileo's arguments that there is something paradoxical about
infinity and infinitesimals
- Basics of set theory
- Cantor's Claim (regarding infinite sets having proper
subsets of the same cardinality)
- Cantor's Theorem
- Platonism, Kantianism, Logicism, Formalism,
Intuitionism, Radical conventionalism
- Russell's Paradox
- A Godel Sentence, and how it entails the First
- Godel's First Incompleteness Theorem
- Godel's Second Incompleteness Theorem
- What a Turing Machine is, and how to make a simple
program for one
- What a universal Turing machine is
- The Church-Turing Thesis
- The Turing Test
- Kolmogorov Complexity
In addition to the listed office hours, I encourage you to make
appointments. I will be available quite a bit. Please try to come to
office hours with specific questions in mind. You can of course come
with a general request for help, but it is always helpful if you spend
a little time thinking about how I can best help you
I will frequently update an online schedule of readings and
assignments. It is your responsibility to check the www pages for the
class at least every other day!