Philosophy 309: Logic, Language, and Thought
Professor: Craig DeLancey
Office: CC 212 A
Office Hours: MF 3:00 - 4:00, W 10:30 - 11:15, and by appointment

This class takes as its themes three questions:
  1. How do we come to know necessary truths through reason alone?
  2. Are there any limits to what we can know through reason alone?
  3. 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 the class.

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

Logicomix, by Apostolos Doxiadis and Christos Papadimitriou
Also available for free, and hopefully helpful to you if you need to review any logic, will be:
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 class.

The grade will be determined in the following way:
Homeworks: 60% (about a third of this will be projects)
Exams: 40% (20% each)
I accept no homeworks by email unless specifically so stated.

Projects will often be reviewed in the class period where they are due. For this reason, late homeworks will not be accepted for credit.

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 the class.

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 answers.

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, 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 Dean.

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: Office Hours
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 out.

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!