## Food supplements – to take or not to take, voici la question!

Last time we analyzed an argument by applying the 7^{th} rule for checking a syllogism’s validity. We showed that if one of the 2 premises is negative, then the conclusion MUST be negative as well.

I asked you to think of how you would argue FOR the position that taking vitamins makes a qualitative positive difference in one’s health. If we are to formulate an argument in its correct form, we need to comply with ALL 7 rules for validity.

Here they are again in a summary list:

Every syllogism to be valid (that is correctly formed), must abide by all seven rules:

- Has 3 and only 3 terms
- No middle term in the conclusion
- If a term is ‘distributed’ in the conclusion, it must be ‘distributed’ in one of the premises
- The middle term must be distributed once.
- No conclusion can be drawn from 2 negative premises
- If the 2 premises are affirmative, the conclusion MUST be affirmative as well
- If one of the 2 premises is negative, then the conclusion MUST be negative as well.

On to constructing OUR argument. Remember, that when we formulate a syllogism, we start with our conclusion and work backwards.

Here is our hypothetical conclusion in ordinary language:

- Therefore, taking supplements improves one’s health

Before we go any further, we have to add a quantifier and rewrite the proposition so that a copula appears. First we reflect – **Do we intend to defend the assertion that ALL taking of supplements improves one’s health or just SOME taking of supplements?**

To be on the safe side, it is more truthful and easier to defend an I proposition, or SOME taking of ‘vits’. After all, some vitamins might be so poorly made NOT to be efficacious.

Next , in order to uncover the copula, we need to ‘tweak’ our second term resulting in:

Therefore, some **taking of supplements** is **a habit that improves one’s health**

Now 2 of the allowed 3 terms pop up clearly.

We can label them and determine the distribution based on our ‘DUDU & UUDDs’ chart. Remember that a term IN FRONT of the copula is in the subject position and a term which FOLLOWS the copula is in the predicate position. We determine the TYPE of proposition by the quantifier (All, Some, No, Some…not)

Type of Proposition | Subject position | Predicate position |

A (All) | D | U |

I (Some) | U | U |

E (No) | D | D |

O (Some….not) | U | D |

Another reason for starting to create or analyze a syllogism ‘bottom up’, that is to say WITH THE CONCLUSION, is that the minor term (represented by S FOR THE ENTIRE SYLLOGISM) is always the term that precedes the copula in the conclusion and the major term (represented by P FOR THE ENTIRE SYLLOGISM) always follows the copula in the conclusion.

Here is our conclusion properly labeled:

I statement – Therefore, **some taking of supplements** (Su) is **a** **habit that improves one’s health** (Pu)

So as we end this discussion, we have the following information about our syllogism:

S term = taking of supplements

P term = a habit that improves one’s health

Next time, we will come up with our 3^{rd} term (see rule 1) which is the M or middle term.

Until next time, keep thinking!

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