Classical yoga (the Samkhya framework Patanjali inherits) draws one fundamental line.
Purusha is pure consciousness: the seer, the still witness at the centre, recognised rather than manufactured. It does not act; it is aware.
Prakriti is nature: everything that is not Purusha, including the body and including the mind. The senses, the ego, the intellect, thoughts, and the gunas that colour them are all Prakriti in motion.
The confusion the whole path unwinds is that we take ourselves to be Prakriti, the layers and the story and the mind, when what we are is the awareness those things arise in. This is the still point mapped at the centre of the Layered Self, and explored further as the three aspects of self-realisation.
One word, two natures
The Stoics put their whole teaching into a single directive: live according to nature. Set that beside this page and yoga can look like the flat refusal of it. Nature (Prakriti) is what the seer keeps mistaking itself for; freedom is telling the two apart. One tradition says align yourself with nature. The other seems to answer: you were never nature at all.
Most of that argument is an accident of translation. The nature in the Stoic sentence is physis: the order running through things, and our own reasoning, social nature as a strand of it. The nature this page draws a line through is Prakriti: the changing field itself, body and senses and thought-weather. Two different ideas are sharing one English word. And for what the Stoic directive actually points at, Patanjali has a word of his own: when the fluctuations settle, the seer comes to rest in what it really is, its own nature (svarupa, Sutra I.3). The next sutra names the alternative: otherwise the seer takes on the shape of the fluctuations (I.4). That is yoga's picture of the unfree life. Not living against nature: living according to the weather.
So yoga can say the Stoic sentence in its own grammar, and it means two things by it. Work with the grain of things: Patanjali's image for the whole method is the farmer who waters a field by cutting the dam, not by carrying buckets; a cause does not force nature into activity, it removes the obstacle and lets things move by their own nature (IV.3). And be what you actually are: the sky, not the weather crossing it. Turned outward, that posture becomes conduct. Ethics (Yama) and discipline (Niyama) are what not-fighting-reality looks like when it meets other people, and your own habits; contentment (Santosha) is its distilled daily form. Nor is nature the villain of the map: the classical texts say the seen exists for the sake of the seer, for experience and for freedom (II.18, II.21). The world is not an enemy to defeat. It is what seeing is for.
The place the two traditions genuinely part is worth keeping, not smoothing. For the Stoics you are a part of nature, so living according to it means participation: reason exercised in the world, duty done the way a grapevine bears fruit. For classical yoga the seer is not a part of Prakriti at all: it is the witness of it, and the goal the path's very last word names is aloneness (kaivalya, Sutra IV.34): the two finally known as two. One map says: you belong to the order, so play your part. The other says: you were never the moving order, so know yourself as the seeing of it. The shared discipline, a life that stops quarrelling with the way things are, is real. So is the difference about who, in the end, you are. YogoLogo keeps both, the way it keeps the witness and no-self side by side without forcing a marriage.