Recently, my daughter asked me if I believed in heaven.

“Well,” I said, carefully choosing my words, “there’s very little evidence to suggest that life or consciousness persists after death. To date, no one who’s died has come back to tell us that there’s a heaven or any form of existence after the body’s life-sustaining functions cease – apart from very spurious testimony from the likes of psychics and preachers. At best, heavens seems improbable.”

I could tell this answer disappointed her. I hastily added: “But, I would like it very much if there’s a heaven or some kind of life after death. I hope there is.”

She nodded her head and looked somberly out the window of our car, her nine-year-old brain cogitating for one of the first times the very hard dilemmas of human existence.

“I hope so too. Death, not feeling anything or doing anything, just seems so wrong and sad when being alive is so much fun.”

Being a parent is a prodigious challenge – not, as some might say, in the gritty details of changing diapers, getting recalcitrant children to school on time, or sharing the family car, but rather in the slow process of seeing innocence and naïveté give way to maturity. Don’t get me wrong, I love that my daughter is now old enough to be able to wrestle with complex philosophical and moral dilemmas. It brings me great joy to discuss the trolley problem or the hard problem of consciousness with her. It’s also difficult – painful in truth – seeing her complexity of thought come with a concurrent rise in sadness and cynicism. I take no particular delight in robbing her of her childish fantasies, of heaven or Santa Claus or her brute allocations of good and evil.

But the privilege of parenthood is that a parent has the opportunity to equip their child with the right tools for adulthood – not, mind you, to create a little carbon copy of themselves, but to give them a basic framework for making their own decisions and thriving into their own place and time. I don’t want my daughter to share my dreams, mimic my interests, or follow in my path. I want her to be prepared for an increasingly complex and challenging world, armed with the best implements for making choices that benefit her and, to any extent, fulfil her moral obligation to make the world a bit better of a place.

As she begins to grapple with the monumental rational and moral problems that come with being human, I would like to offer her these words, with love:

Human beings are hard-wired for survival. In purely practical terms, this means that we’re inherently self-interested and lazy. I say this not pejoratively or with malice toward our species; our selfishness and drive to conserve energy served us well for hundreds of thousands of years. Alas, our brains have not kept up, evolutionarily-speaking, with the rapid advances in technology and science that our species has made in just a few millennia. We remain cave dwellers at heart, inhabiting a world more diverse and sophisticated than our brains can process.

Know this: you are driven to seek pleasure and avoid pain, to protect yourself and those closest to you, and to distrust difference and change. And, when two or more options to achieve a goal or fulfil a desire are present, your mind will urge you to take the path of least resistance – to make the choice that requires the least amount of time, sweat capital, and cognitive investment.

Now for the good news. Our brains have also evolved a considerable capacity for reason and compassion. Reason allows us to observe and reflect on the world around us, to gather facts and process them. Reason allows you to come close to the truths of existence by carefully sifting the input of your senses, listening to the observations and conclusions of others, and applying your curiosity and skepticism to that raw data. Reason will help you make the best decisions for yourself and others. Understand, however, that reason is a process and not a destination. No human being will ever be all-rational, all the time. Humankind, barring another step in our evolution or through tinkering with our own genetics, will never be a perfectly rational species. We must live with our biases, our pettiness and self-serving nature, our messiness. With reason, we merely get better at managing our worst tendencies over time.

So pure reason isn’t enough to live a good life. The universe is awesome in its extent and organization, but tells us very little about how we ought to act toward ourselves and others. Compassion is a necessary adjunct to reason, for the purely rational mind (an impossibility, as I’ve said), will be prone to bleak and cold interpretations of the nature of existence and drastic moral decisions; moreover, we are emotional beings in addition to rational ones. Compassion is the potential to consider other people’s needs alongside your own, to see all living things as equal in dignity and worth to your own, and to forgive yourself or someone else when wrong has been done. Reason will help you to think clearly, and in most cases guide you to moral clarity as well, but when it comes time to transform your intellectual commitments into meaningful action, let compassion and reason unite.

How well you succeed in terms of happiness and the good you do for the world will depend on your ability to ration these two opposing forces of the mind: your drive to be self-interested and energy-conserving, and your capacity for reason and compassion. The situation is made more difficult by two things. Firstly, selfishness and laziness bring immediate happiness – while thinking of another human being, especially one you don’t know or whose beliefs, way of living, or identity are different from yours – appears to come at a cost of your own well-being. Secondly, applying reason and compassion to circumstances that pull on your instinctual self-interest require energy to overcome.

In the course of your life you’ll be confronted with innumerable decisions that appeal to your self-interest and desire for pleasure over pain. You’ll be presented with belief systems that provide the easy, reassuring answers your mind craves. It isn’t always necessary to be rational about everything. Life’s meaning, that is to say that which suffuses it with purpose and worth, is found in small, seemingly unnecessary actions. These are vital, too. Dance in rain puddles. Sing by a campfire. Eat the piece of cake. But on the hard, big issues – employ your reasoning abilities as best you can. Use logic and the empiricism of science to wrest the truth from a world that’s rife with fashionable nonsense. The energy investment is worth it.

The world you inherit is on the brink. Now more than ever is the fate of this species in question, and if we are to survive it will surely depend on how well you and your generation employs reason and compassion. Proceed from the basic assumption that the purpose of moral action is to reduce human suffering (or, to state it positively, increase human happiness). Through that lens, kindness and compassion become rational, too: they are instrumentally necessary to achieve a world where suffering is minimal. Recognize, too, that compassion is ultimately self-serving (the plot twist that most of us have yet to recognize); lifting others up also lifts us too, less violence today reduces the probability of violence tomorrow, responsible caretaking of our planet ensures there’s a habitable oblate spheroid humbly dancing with our yellow sun in place for your children. It might seem that being compassionate comes at a cost of your own happiness, but it’s more accurate to say that it’s a short term loss for a long-term reward. It’s not the kind of immediate satisfaction that comes with impulsive choices made in the moment creates, but it’s a form of survival if you take the long-view of history and your place within it.

This long view of history is vital, because one day you will be where I am now: of an age where “what will I do?” is less on the mind than “what will I leave when I’m gone?” Many of your kin will be happy enough to die with “enough toys.” Stuff, too, brings temporary contentment. Others will cast an eye back and long for more time with those they loved, suddenly and too-late aware that they misspent the only currency that bartering and begging cannot increase. Most, I venture, will wonder what will be said of them when they gone, and how the world was helped or harmed by their momentary presence. I hope that you live your days knowing that you will one day wonder if the world took note of you, and if it will be better because you lived.

Be a critical thinker. Live to lead and rarely to follow. When conflict gives you a choice to be right or to be kind, choose kindness. When you’re happy, notice it and mark it down.