Ponens, tollens, pollen, tones?

My dearth of knowledge in theoretical philosophy is a pretty big setback, especially in the higher level philo modules. Phrases are flung about the class casually and I have to note it, usually in bahasa baku, if the terms are not in (plain) english.
The next task, deciphering my scrawly writing in order to google said word/phrases, is no simple one... not just because of the writing but due to the permutation and combination games played with the various alphabets in the search bar, trying to get the right word.
Anywho, a lot ponen-ing, tollen-ing, and a bunch of modus-es, have been going around the class for the past couple of weeks, time to get the terms down pat!

syllogism and ornithology
more penguin facts and humour here (:

4 simple argument forms seen in philosophy classes. Of the 4, the modus ponens and modus tollens arguments are most frequently used. The last two are intuitively graspable and with similar logical laws to the first two, so I didn't bother to expand the explanatory portion.

(1) Modus ponens:
Short for modus ponendo ponens,
Latin: the way that affirms by affirming.

(i) If P, then Q.

(ii) P.

Conclusion: Therefore, Q

The first premis is an "if-then" or conditional claim

P implies Q,

The second premise is that P, the antecedent of the conditional claim (i.e. the if part), is true.

Thus one could logically conclude that Q, the consequent of the conditional claim (i.e. the then bit) must be true too.

If the if is true, then the then is true.

(2) Modus tollens:
Short for modus tollendo tollens,
Latin: the way that denies by denying.

(i) If P, then Q.

(ii) ¬Q

Conclusion: Therefore, ¬P

Again, the first premis is an "if-then" or conditional claim
Once more, P implies Q,
The second premise is that Q, is false.
Thus one could logically conclude that P is false.
(for those not too familiar with the symbols: if P, then Q. Not Q. Therefore, not P)

By transposing the premise with material implication (i.e. the if-then statement), one can switch modus ponens to tollens and vice versa.
If the then is false, then the if is false.


(3) Modus ponendo tollens:
Latin: mode that by affirming, denies.

(i) Not both P and Q
(ii) P
Conclusion: Therefore, not Q


(4) Modus tollendo ponens:
Latin: mode by which denying, affirms.

(i) P or Q

(ii) Not P

Conclusion: Therefore, Q

I will chuck in a bunch of examples in another post. For now, back to thesis writing *raaaawr*