So what happens?
As Freud says, though there are people who are universally admired for their selflessness, not many of us, so act.
Of-course as Tanya, the primary book of Jewish mysticism teaches, we are a composite.
Within each and everyone of us is two opposing forces.
The first is the Divine force – this force gives energy to our Divine spirit, the part in us that seeks G-d, unconditional love etc.
The second force is called the animal – like all animals’ driven by two primary instincts (all others are simply offshoots) love (namely the desire for that which I love, namely, pleasure, comfort etc.) and fear (namely, the desire to not encounter that which I fear, for example pain, anxiety etc.)
Hence within us a conflict between ideals and instincts, between our higher and lower, between (in a way) our mind and our heart (in this context, instincts.)
Now the good news is we have a third soul – this is an independent mind – this should not be underestimated.
What makes a person unique is not having a mind (many animals actually – even bees have far greater mathematical skill then humans) rather it is having an independent mind – a mind that can think objectively (as opposed to like a computer which is merely doing the will of its user.)
As such, we are both interested and capable of discerning (the art of comparing and evaluating.)
The additional quality of the independent mind is that though as we can all tell, it takes much effort (say dieting etc.) nonetheless if we exercise it, we can control our instincts.
So in summation the healthy person is the one who a. recognizes that s/he is a composite of both Divine altruism and animal self-center instincts, and using their mind – and more importantly the wisdom of the Torah (for in truth, by the time an instinct hits our mind, it already is “kosher,” rationalized (which is how people do pretty awful things…) we ensure, through self-discipline that we are “Kosher.”