I'm trying to learn how to present an argument with epistemic defeaters in a professional way.

Let's say we have the following arguments when you're inside your home and are considering if it's raining outside or not.

  1. Lisa tells you that it's raining outside. (E1)
  2. Dante tells you that it's not raining outside. (E2)
  3. You can hear sounds from the roof which could be raindrops falling. (E3)
  4. It has been raining the hours before. (E4)

H = It's raining outside E = Evidence

Is this the correct way to write it?

P(H | E1 ^E2 ^E3 ^E4 ) > P(H)


  • 1
    Immediately stop &recognize that what you gave is an inductive argument. That is, this is about science. You need evidence. Evidence means you must use at least one of the famous human senses to detect: sight, hearing, smell, taste & touch. As a human your senses can be wrong which means you can err. This no way to absolutely have a CERTAIN CONCLUSION. No science can lead to certainty for the same reasons just mentioned above. Deductive reasoning is no based on human senses. So you would need to know this from the start. You will never be 100 % certain with what you have, period. You can err.
    – Logikal
    Commented Dec 25, 2020 at 12:56
  • Many thanks Logikal! Witnesses are fallible as evidence. Commented Dec 25, 2020 at 17:41


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