That's a shame, because basic Aristotelian philosophy used to be schoolboy stuff.
Interestingly, the only things we can actually know with certainty are purely abstract, like a^2 + b^2 = c^2. Is that within "the observable world?" Meanwhile it's entirely basic that our senses cannot be trusted. There's a fairly compelling argument to be made that sensory observation isn't a particularly good means of gaining knowledge. My own philosophical inclinations are pragmaticist though, so I believe abductive reasoning can, practically speaking, suffice for a useful if not entirely correct understanding of many phenomena.
Interestingly, the only things we can actually know with certainty are purely abstract, like a^2 + b^2 = c^2. Is that within "the observable world?" Meanwhile it's entirely basic that our senses cannot be trusted. There's a fairly compelling argument to be made that sensory observation isn't a particularly good means of gaining knowledge. My own philosophical inclinations are pragmaticist though, so I believe abductive reasoning can, practically speaking, suffice for a useful if not entirely correct understanding of many phenomena.