OK, let’s leave off P1 and split out C from P2. The new syllogism will read:
P1*. If A then C
P2*. C
C*. You should think A to be true.
This conclusion does not follow from the premises. It is the classical fallacy of affirming the consequent. A different syllogism, with additional or changed premises as I have offered previously, might work, but it would be a different syllogism. As this syllogism stands, it is invalid.
This is sort of tangential, but it’s important to discussions of philosophy generally for two possible reasons:
- If you are under the belief that the conclusion follows from the premises, it is important to explain why that isn’t the case because this is a pseudo-logical form that comes up often.
- If you are not under the belief that the conclusion follows from the premises, it is important that you concede the point, because without a concession on a rigorously demonstrable fact of formal logic, it is difficult to maintain a presumption of good faith.
Yep, I flubbed that one, let me try again using you example of finding a close parking space and not murdering.
Both seem to be clearly on a spectrum of things that you should do when you can. And the ranking can be in terms of how much it matters that you do one or the other. And there is an inuitive sense in which if you fail to not murder, it matters a whole lot, while if you fail to find a close parking space, it matters only a very little. We might ask some different questions when evaluating whether or not to murder versus whether or not to find a close parking space, but we will also ask different questions about murder and theft.
It’s a difficult comparison, because murder and parking are at completely different ends of the spectrum. But there is a cognizable spectrum. It’s also worth noting that the theory I’m espousing, that there is a generally objective ranking but not objective truth in any individual case, already explains a phenomenon of how our oughts work: choices at the lower end of the spectrum are less clearly ranked than those at the high end. If we’re ranking murder against theft, there’s a clear and seemingly objective order. But if we’re ranking parking versus wearing a blue tie, it becomes harder to rank them. But this is to be expected, because, mattering so little, context drowns out the ranking in virtually every case. If you think of the spectrum in units of oughtness, the lower will have so few oughtness units that every experience of the question will be surrounded by other questions that together swamp the oughtness. If I’m determining where to park, am I running late? am I out of shape or injured? Am I driving someone else who I want to convenience? Am I the owner or employee of the place I’m going such that I don’t want to block spots for customers? Similarly, in picking a tie, what other ties do I have? What color is my shirt/jacket/eyes? Am I testifying in court, or am I the lawyer, and if the latter, plaintiff or defense? These questions have so much more oughtness in them that the oughtness in the question itself are within the margin of error. Similar questions about the oughtness of murder or theft don’t tip the balance, because the oughtness of murder is enough to make the influence of most other ought questions insignificant.