Weight is caused by one ...

Weight is caused by one element being situated in another; and it moves by the shortest line towards its centre, not by its own choice, not because the centre draws it to itself, but because the other intervening element cannot withstand it.
Weight is caused by one element being situated in another; and it moves by the shortest line towards its centre, not by its own choice, not because the centre draws it to itself, but because the other intervening element cannot withstand it.

Quotes from the same author

All our knowledge has its origins in our perceptions.
It had long since come to my attention that people of accomplishment rarely sat back and let things happen to them. They went out and happened to things.
Iron rusts from disuse; water loses its purity from stagnation... even so does inaction sap the vigor of the mind.
Nothing strengthens authority so much as silence.
He who is fixed to a star does not change his mind.