I read your story with the appropriate surprise and indignation.
Needless to say, if your account is accurate, you were 100% correct, and your so-called professor sounds like he does not know logic, and lacks ordinary intelligence and honesty.
'Some P are Q' does not imply 'some P are not Q', but is subcontrary to it, since the former is implied by the contradictory of the latter, namely 'all P are Q'. This is graphically stated in the 'square of oppositions'.
There is in Talmudic logic a reading of 'some P are Q' as implying 'some P are not Q' - but such reading of 'some' as definite is not used in common, Western logic - where 'some' is indefinite.
And indeed, 'some' must be indefinite for purposes of induction, as you well point out in your examples. If I observe some fishes swimming, I must be linguistically able to express this without committing myself to either of the outcomes some fishes do not swim or all fishes swim. The matter must remain open.
Indeed, normally, not knowing more than this, we would naturally generalize from some fishes swim to all fishes swim. After which, if we ever came across fishes that do not swim, we would have to particularize and admit that some fishes do not swim.
So your teacher is absurd in his teaching and unworthy in his closed-minded reaction to your correct objections. You can tell him I said so! But as for you, do not let this episode discourage you - you obviously have good potential as a 'critical thinker' who does not let himself be moved by authority or by peer group pressure!
Consider yourself as having passed through a live test and succeeded with flying colors. View this as an object lesson well learned. Don't feel bad towards your teacher or his other pupils, as human beings all have their limits in intellect and virtue. Accept the situation and move on.
As for the one paragraph test: "Explain the relationship between the following terms: truth, logic, critical thinking, being, definition, genus, species." - I wonder what inanity your teacher would himself briefly answer to that question. Of course, you're right 'being' and 'reality' are very different concepts, since being can also be illusory, i.e. unreal.
Look for another teacher of logic first chance you get. But don't give up on logic and philosophy.
Hi Disgruntled.
Hang in there and finish the job!
If you want to reprove the professor and fellow students for their behavior you might want to read them our correspondence in class.
Alternatively, print it out and hand it out. At least to the professor. Maybe even to the faculty head.
Best, Avi.
P.S. By the way,the reason why the Talmud works that way is that it is essentially a conventional, rather deductive discourse. Probably your professor is so conventional minded that he actually thinks that way, i.e. with little inductive method. Hence his bad reaction to your intellectual independence.
