A is the Novus Ordo
"B" and "C" are each predicated of A
If A is B and A is C, then B is C.
If a syllogism relies on something implied, but doesn't state it, it remains syllogistic reasoning though it is called an enthymeme.
1. The SSPX believes the Novus Ordo rite is the "ordinary rite of the Catholic Church"
That is, A is B
Necessarily implied:
If something is an "ordinary rite" it is the "official rite".
If it is the "Catholic Church", it is "holy".
2. The SSPX believes the Novus Ordo rite is "poisonous" and "strangles grace".
That is, A is C
Necessarily implied:
If something is poisonous, it is less than good.
Conclusion: The SSPX believes that an official rite of the HOLY Catholic Church can be anything less than "good".
That is, B is C - more strictly syllogistic: "an ordinary rite of the Catholic Church" can be "poisonous"
Yes, we can most certainly conclude that. It is valid reasoning based on predication and substitution of what is already implied. The Church does not require something to be a strict syllogism to be validly reasoned or concluded, nor does She require one to study Logic in order to be able to reason.
It is the same solid reasoning as this:
1. his father is a man
2. his father is bad
IF these two are true, we conclude that, "a man can be bad".
If the conclusion is not true, Jamie, then, are you claiming the SSPX does NOT believe "an ordinary rite of the Catholic Church can be harmful"? So, the SSPX only believes an ordinary rite can be nothing less than good and useful?