Because a teacher is assigned to only work one subject because that's where he/she is good at. The “subjects” taught at school are coarse approximations to human knowledge. Take modern genetics, for example. Even at undergraduate level it is across Biology, Chemistry, Statistics, and quite a lot of Physics. It requires smatterings of theology, law, culture, and even history to inform the Ethics of the work. The undergraduate needs to have been exposed to all of that, even if they were not examined in it. Education is not a catechism, to be learned in rote; it is a buffet at which you can gorge, or pick, or sample, or evade, as suits you. It is not something to be endured, but something to be enjoyed, something full of surprises, unexpected stimulii, thrills (and disappointments), and self-discovery.
Is it better to study one subject or multiple?
It's more effective to study multiple subjects each day to help you stay focused, than to deep-dive into one or two subjects. For example, if you're preparing for exams in math, history, physics, and chemistry, it's better to study a bit of each subject every day.
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Because a teacher is assigned to only work one subject because that's where he/she is good at. The “subjects” taught at school are coarse approximations to human knowledge. Take modern genetics, for example. Even at undergraduate level it is across Biology, Chemistry, Statistics, and quite a lot of Physics. It requires smatterings of theology, law, culture, and even history to inform the Ethics of the work. The undergraduate needs to have been exposed to all of that, even if they were not examined in it. Education is not a catechism, to be learned in rote; it is a buffet at which you can gorge, or pick, or sample, or evade, as suits you. It is not something to be endured, but something to be enjoyed, something full of surprises, unexpected stimulii, thrills (and disappointments), and self-discovery.
It's more effective to study multiple subjects each day to help you stay focused, than to deep-dive into one or two subjects. For example, if you're preparing for exams in math, history, physics, and chemistry, it's better to study a bit of each subject every day.
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