Although I may not be yours, I can never be another’s. - Mary Wollstonecraft

How can a rational being be ennobled by anything that is not obtained by its own exertions?

Thus strangely are our souls constructed, and by such slight ligaments are we bound to prosperity or ruin. When I look back, it seems to me as if this almost miraculous change of inclination and will was the immediate suggestion of the guardian angel of my life — the last effort made by the spirit of preservation to avert the storm that was even then hanging in the stars and ready to envelop me.

If the study to which you apply yourself has a tendency to weaken your affections and to destroy your taste for those simple pleasures in which no alloy can possibly mix, then that study is certainly unlawful, that is to say, not befitting the human mind.