For once I agree with Paul Graham. I expect his post to be surprisingly unpopular with this crowd, as it sleights a core tenet of our postmodern age. Namely, he's arguing for a form of objective truth and of "the good". A statistical derivation of this good for sure (and qualitative as opposed to a Benthamist, quantitative utilitarianism), but a good nonetheless. But I applaud PG for taking this stance. Truth is not…
While you claim to oppose the postmodern idea that there is no truth, you’ve ceded the premise to the postmodernists by framing truth in their terms of objectivity and subjectivity. The success of the postmodernists was precisely to discredit all “subjective” truths by way of distinguishing them from “objective” truths, which no common person can deny. A stronger position is one that does not require the truth to be…
In the case of 2+2=4, this is formalized by the Peano axioms [1], which define addition of natural numbers. However, in tropical geometry [2], addition returns the minimum of the numbers, not their sum.
The author of the original tweet makes this point, and I strongly agree with it: https://twitter.com/ConceptualJames/status/12889571678449623...
As for 2.4 + 2.4 = 5, I think the tweet author is being a bit sloppy there in his explanation. But consider 0.1 + 0.2. Ask a human, and they'll tell you it's 0.3. Ask a computer, and it'll likely tell you it's 0.30000000000000004. The point is that in both scenarios, 0.1, 0.2, and addition are defined differently.