“To know what one ought to do is certainly the hardest thing in life. ‘Doing’ is comparatively easy,” pioneering 19th-century astronomer Maria Mitchell (August 1, 1818–June 28, 1889), who paved the way for American women in science, wrote as she contemplated science and life in her diary. A century earlier, the French mathematician Émilie du Châtelet, who defied the vocational expectations of her era to become a world authority on Newtonian physics, articulated the same sentiment in writing about gender and the nature of genius: “One must know what one wants to be. In the latter endeavors irresolution produces false steps, and in the life of the mind confused ideas.”

And yet there are myriad conditions and conditionings outside ourselves that color and confuse that knowing — not even the fortunate few whose inner eye is animated by an uncommon clarity of vision can claim such a thing as absolute purity of purpose. Even if we were to lay aside the perennially thorny question of free will, the choices we make in life in discerning what we ought to do are invariably limited by our perception of what we can do, which are in turn a function of our individual talents and the cultural canvas of permission and possibility onto which these talents can unfold.

I was reminded of this dependency in a recent conversation with an astrophysicist friend about Maria Mitchell and the following generation of women astronomers, many of whom never married and chose science over family life. We wondered how much of a choice that really was — what the opportunities were for women, decades before they could vote or even attend university, to pursue and excel at occupations only available to men at the time, men who were able to devote their days to science because they had someone at home to launder their long-johns and boil their breakfast porridge.

My friend then relayed a turning point in her own life and career as a scientist: In watching a male colleague emulate their shared elders — those typically and therefore stereotypically masculine scientists of yore — she realized, almost with a shock, that being this person was simply not an option available to her. But with the horror and the wistfulness of the realization also came a tremendous sense of liberation — it was in that moment that she found herself free to create different options, to be a different kind of scientist unbounded by the convention of expectations she could never meet. That she is now one of the world’s most venerated astrophysicists is in no small measure thanks to that moment of permission to choose for herself a destiny beyond convention — one which was, then and only then, not a prescription but truly a choice.

In a full revolution, our conversation reminded me of something Maria Mitchell herself, always eons ahead of her time, had articulated in her diary exactly a decade after America’s first class of women astronomers graduated from her program at Vassar. In an entry from August of 1886, found in Maria Mitchell: Life, Letters and Journals (public library | free ebook), Mitchell considers the interplay of convention and opportunity with relation to gender in light of the then-novel trend of cooking colleges for women:

I am always afraid of manual-labor schools. I am not afraid that these girls could not read, for every American girl reads, and to read is much more important than to cook; but I am afraid that not all can write — some of them were not more than twelve years old.

And what of the boys? Must a common cook always be a girl? and must a boy not cook unless on the top of the ladder, with the pay of the president of Harvard College?

It seems both obvious and necessary to note that the gendered hierarchy and pay scale in the culinary world has hardly changed in the century and a half since. But Mitchell’s larger point has to do with the question of meritocracy — with the necessity of institutions and social structures that nurture excellence in fields freely chosen on the basis of individual interest and talent rather than on societal expectation. Far from looking down upon the culinary arts as demeaning of women, she argues instead that such careers should be chosen only by those, be they male or female, who are truly passionate about them; that, most important, an equal opportunity for pursuit should be offered in intellectual endeavors, so that the choice between cooking and science becomes truly a choice.

With her characteristic wit and spirited wisdom, she writes:

If the food for the body is more important than the food for the mind, let us destroy the latter and accept the former, but let us not continue to do what has been tried for fifteen hundred years, — to keep one half of the world to the starvation of the mind, in order to feed better the physical condition of the other half.

Let us have cooks; but let us leave it a matter of choice, as we leave the dressmaking and the shoe-making, the millinery and the carpentry, — free to be chosen!

There are cultivated and educated women who enjoy cooking; so there are cultivated men who enjoy Kensington embroidery. Who objects? But take care that some rousing of the intellect comes first, — that it may be an enlightened choice, — and do not so fill the day with bread and butter and stitches that no time is left for the appreciation of Whittier, letting at least the simple songs of daily life and the influence of rhythm beautify the dreary round of the three meals a day.

Mitchell herself fully embodied her credo of authenticity and hard work, writing in her diary at the peak of her improbable, pathbreaking career:

The best that can be said of my life so far is that it has been industrious, and the best that can be said of me is that I have not pretended to what I was not.

Complement with Mitchell on why women are better suited for astronomy than men, the story of how the word “scientist” was coined for the Scottish mathematician and Mitchell’s contemporary Mary Somerville, and pioneering astronomer Vera Rubin, who confirmed the existence of dark matter and whose own career was inspired by Mitchell, on what it’s like to be a woman in science, then revisit Simone de Beauvoir on how chance and choice converge to make us who we are.

UPDATE: Find more of Maria Mitchell, her unusual life, and her far-reaching legacy, in my book Figuring.