...some people requested that I be prohibited from studying.
One time they achieved it through a very holy and simple mother superior who believed that studying would get me in trouble with the Inquisition and ordered me not to do it. I obeyed her for the three months that she was in office in as far as I did not touch a book, but as far as absolutely not studying, this was not in my power.
[...]
Even the people I spoke to, and what they said to me, gave rise to thousands of reflections. What was the source of all the variety of personality and talent I found among them, since they were all one species?
[...]
Sometimes I would pace in front of the fireplace in one of our large dormitories and notice that, though the lines of two sides were parallel and its ceiling level, to our vision it appears as though the lines are inclined toward each other and the ceiling is lower in the distance than it is nearby. From this it can be inferred that the lines of our vision run straight, but not parallel, to form the figure of a pyramid. And I wondered if that was the reason that the ancients questioned whether the earth was a sphere or not. Because although it seemed so, their vision might have deceived them, showing concave shapes where there were none.
[...]
Once I saw two girls playing with a top, and hardly had I seen the movement and the shape when I began, in my insane way, to consider the easy movement of the spherical shape and how long the momentum, once established, remained independent of its original cause, the distant hand of the girl. Not content with this I had flour brought and sprinkled on the floor in order to discover whether the spinning top would describe perfect circles or not. It turned out that they were not perfect circles but spirals that lost their circular shape to the degree that the top lost momentum.
Sister Juana Inés de la Cruz, 1691 (tr. Pamela Kirk Rappaport)