In the teachings of yoga, breath (prana/energy) is life, life is breath (prana/energy). If no breath (no prana/energy), there's no life. Similarly, in science, if no oxygen, no food, no nutrients, no minerals, no water, no energy, no supportive systems that take in, breakdown, digest, filter, modify, absorb and distribute energy/oxygen/chemical compounds/nutrients/minerals that supports life, there's no life.
The life, or the existence and function of the body and the perceptive cognitive thinking mind, is not possible if without the breath coming and going, as well as many other different body parts, organs, senses, nerves, neurons, blood vessels, glands, skins, bone structure, joints, muscle groups, tendons, ligaments, hormonal secretions, systems and elements working together to provide the supports that enabling this life existence of the body and mind being what they are, to be existing and functioning, selflessly and impermanently.
The breath is not the thinking mind, and it doesn't belong to the thinking mind. Each different component, system and element, are not the thinking mind, and they don't belong to the thinking mind, while all the different components, systems and elements are working together, supporting and influencing each other, that enable everything to be existing and functioning as they are, selflessly and intentionlessly.
The existence and function of the breath is only possible under the support of many other parts of the respiratory system, that is also relying on the support of many other body systems, where all kinds of systems also relying on one another as well as the many different supportive components and elements, where all kinds of supportive components and elements also wouldn't be available if without some other supportive elements respectively, and so on.
The breath is selfless and impermanent. So as all the other supportive components, systems and elements are all selfless and impermanent. There's no 'I' in the breath, as well as there's no 'I' in all kinds of supportive components, systems and elements that enable the life of this selfless and impermanent body and mind to be existing and functioning.
There's no 'I' existing in the existence and function of this selfless impermanent body and mind. The function of the thinking faculty is selflessly being influenced by energy, relying on the support of many different supportive components, systems and elements. Even when the thinking mind has certain freewill command over the physical movements, thinking, actions and reactions, speech and expression, it still depends on the selfless function of the central nervous system connecting to the peripheral system, provided if the central nervous system as well as the peripheral system is functioning normally under the support of all kinds of supportive components, systems and elements respectively. Even when the thinking mind has certain freewill power to exert as much energy as possible into performing certain actions to maintain the good condition of the physical body, it still doesn't change the truth of selflessness and impermanence in everything, including the existence and function of the physical body as well as the thinking mind itself.
It's only the ignorant egoistic impure thinking mind has an idea of 'I' existing in the form of thinking, out of ignorance and egoism, believing that 'I' exists as an individual being, claiming a personal identity attaching towards certain qualities of names and forms that are selfless and impermanent, to be identifying as 'I', as well as claiming possession or ownership towards all kinds of selfless impermanent names and forms that don't belong to anyone as 'mine' or 'my'. From the idea of 'I', arise all kinds of impurities, intentions, desires, possessions, discontentment, fear, pride and greed, that give rise to so much unnecessary disturb, unrest and suffering arising from within the modification of the mind, as well as projecting into the surrounding environment, while proudly thinking and believing that, "I am in control of myself, my life, my body and my mind, I achieve everything by my own freewill, intention and effort, and everything is according to my desire of how I want it to be."
If without all kinds of supportive components, systems and elements enabling this mind being what it is, then what is this thinking mind? What is pride and arrogance?
The thinking mind is being aware of the existence and function of the breath, which the breath itself is one of the supportive influential elements for the thinking mind to be functioning, where all kinds of supportive elements are selfless and impermanent, without egoistic intention to be working together being one of the supportive influential elements for enabling one another and everything else to be happening, existing, changing, and cease existing.Most of the time, the thinking mind is not aware of the breath and/or any other components, systems or elements at all, being occupied with the restless selfless modification of the mind, being busy with the perception of names and forms through the senses and the thought process of ceaseless reactions reacting towards the sights, sounds, smells, tastes, sensations, imaginations, projections, anticipations, memories, and so on, that give rise to attachment, identification, comparison, judgment, desires of craving and aversion, expectation, and so on. But, the breath and all the other components, systems and elements are still ceaselessly performing selfless intentionless actions, working together, supporting and influencing one another being what they are, as they are, until they cease performing action at due time and cause.
The thinking mind is also one of the selfless impermanent components. It's selfless and impermanent, existing and functioning under the support of all the other supportive components, systems and elements. It's not 'I', and there's no 'I'. There's no 'I' existing in control of the existence and function of the thinking mind. Similarly, if without the function of the perceptive cognitive thinking mind under the support of many different supportive elements, what is worldly life existence, what is pleasurable enjoyment and painful suffering?
Meanwhile, from the selfless impermanent thinking mind itself, there might or might not be an awareness being aware of the veil of ignorance, and there might or might not be arising a desire to be liberated from ignorance and the suffering that derived from ignorance.
Initiated by the thinking mind itself, it can be performing all kinds of disciplinary to discipline, purify and quiet the modification of the mind, which enabling self-inquiry and self-realization to be happening, through the annihilation of the idea of 'I' and the veil of ignorance.