"Anyone who loves the law or sausages should never watch either being
made" -proverb, often referred to by the idiom 'how the sausage gets
Stoicism does not advise us to look away from unpleasant truths. In Aurelius' Meditations he argues for deeply recognising the reality and certainty of our death, and to spend a little time every day contemplating it. He says there:
“Meditate upon what you ought to be in body and soul when death
overtakes you; meditate on the brevity of life, and the measureless
gulf of eternity behind it and before, and upon the frailty of
While Stoic thought does not urge us to goad or provoke others with what we think we know either, but I think you are misunderstanding Stoicism, if you think it advocates protecting others from the hard truths of the world. On the contrary, you would need a very clear and strong specific motivation from knowing you would cause lasting harm, to hide truths.
And consider, a child might be horrified to realise the cute animal from their story books was being murdered for a specific treat, and you choosing to hide or obscure that may have allowed them to accrue years more guilt and deaths, a net negative to your supposed good deeds.
I'd say the key thing is motivation. Do you serve their short-term comfort only; or their deeper self (and yours) and it's pursuit of wisdom? Wisdom must always aim to see the world as clearly as possible (I argue it is the faculty of good decision making, cultivated by the practice of finding the integrated centre of our concerns, eg now vs later, self vs other, impulsive vs rational self, etc, our settled, whole, or deeper self, that our dilemmas myst be solved on behalf of). There is wisdom, in knowing how the sausage gets made; whether or not you then wish to eat it, it's constituents remain the same.
I think a Stoic would draw a different lesson from sausage making. Maybe:
"Everything has an end; a sausage has two." -German proverb
Evolution is both endless excrutiating struggle and inevitable death, and also wonder. It is both. Wisdom is to see both, not to tip the scales either way, but observe that there are swings around a balance between them, and if it tips either way likely it will swing back.
If someone is stuck on wonder, then sure maybe they should learn about parasitic wasps, which helped confirm Darwin in his atheism, and they will find out if the knowledge takes the shine off or deepens their wonder, as it did for David Attenborough who passionately defends conserving them. But someone obsessed with the gloomy realities of 'Nature, red in tooth and claw' (from a Tennyson poem about finding deeper truths than that), should perhaps watch an octopus dreaming, which is not only beautiful but indicates something profound in this convergent behaviour of a mollusc, so far seperated from us in our family tree, and the dream we seem to share with them of being anything at all.
Einstein cautioned against losing the cultivation of our sense of wonder:
"The most beautiful experience we can have is the mysterious. It is
the fundamental emotion that stands at the cradle of true art and true
science. Whoever does not know it and can no longer wonder, no longer
marvel, is as good as dead, and his eyes are dimmed." -in his
marvellous essay The World As I See It
Yes we should correct for the human tendency to choose comforting lies. Be we mustn't shun wonder in order to obsess over hard truths either.
"What is the hard truth?" "We are all rascals." "What is the
comforting lie?" "That we wish we weren't."
-possibly a Zen saying, though I can't locate a source
The Stoic way is to find comfort in the bigger picture, that our tribulations are only a moment of light in the darkness, and in that understanding appreciate it exactly for it's ephemerality, temporality, and vast unlikeliness.
This quote is from the Christian tradition, though surely from the part influenced by Boethius and his On The Consolations of Philosophy, which framed Stoic thought to answer Christian questions, written in his cell awaiting execution (certainly there are echoes of Ecclesiastes, also).
"Your Majesty, when we compare the present life of man on earth with
that time of which we have no knowledge, it seems to me like the swift
flight of a single sparrow through the banqueting-hall where you are
sitting at dinner on a winter's day with your thegns and counsellors.
In the midst there is a comforting fire to warm the hall; outside the
storms of winter rain or snow are raging. This sparrow flies swiftly
in through one door of the hall, and out through another. While he is
inside, he is safe from the winter storms; but after a moment of
comfort, he vanishes from sight into the wintry world from which he
came. Even so, man appears on earth for a little while; but of what
went before this life or of what follows, we know nothing." -St
Paulinus of York
Go deeper in your equanimity, and niether close the door to it to others, nor force them through it. Only check, you are where you wish to be, because that is the measure of it.