Paul Jobs was a mechanic, good with his hands and intelligent with his work, which largely focused on cars and then constructing metal parts for laser assemblies in Silicon Valley. “I thought my dad’s sense of design was pretty good,” Jobs told Isaacson, “because he knew how to build anything. If we needed a cabinet, he would build it. When he built our fence, he gave me a hammer so I could work with him.” Fifty years after the fence was constructed, Jobs showed it to Isaacson, still standing and recalled a lesson about making things of quality that he learned from his father. Touching the boards of inside of the fence, he said that “He loved doing things right. He even cared about the look of the parts you couldn’t see.” He said that his father refused to use poor wood for the back of cabinets, or to build a fence that wasn’t constructed as well on the back side as it was the front. Jobs likened it to using a piece of plywood on the back of a beautiful chest of drawers. “For you to sleep well at night, the aesthetic, the quality, has to be carried all the way through.” This philosophy led jobs to at least attempt to manufacture Apple products with the same care, even in the details that would be invisible to the user. When the first Apple II casings were delivered, Jobs noticed a thin plastic seaming that was often the result of the injection molding process, he had Apple employees sand and polish them to be displayed at a computer expo. Jobs even rejected the designs of the original logic boards inside of the Apple II as the ‘lines were not straight enough’.

Any physical theory is always provisional, in the sense that it is only a hypothesis - you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation that disagrees with the predictions of the theory. […] Each time new experiments are observed to agree with the predictions, the theory survives and our confidence in it is increased; but if ever a new observation is found to disagree, we have to abandon or modify the theory.