Perhaps 'selfish' isn't the right word for it as the 'self' is not the goal. But if you define the 'self' as your inner core/soul is it still possible to meditate selfish? If so how to know this and how to prevent this? How to distinguish between 'good' and 'bad' ('achieved') enlightement?
The goal of meditation is certainly 'selfish', i.e., to improve & liberate oneself.
However, the effect of meditation is unselfishness, i.e., the capacity to greatly give to others.
What actually hinders the capacity to give of an attained meditator is the incapacity of others to receive.
Often it is pointless to attempt to give Dhamma because others are too ignorant to receive it.
But if you define the 'self' as your inner core/soul is it still possible to meditate selfish?
One purpose of meditation is to deepen your understanding for anatta, non-self. Meditating as intended, one develops a different view on the self than the definition above, for instance.
If so how to know this and how to prevent this?
On one hand - among other things - one needs to familiarize oneself with the theoretical concepts of:
- the twelve nidanas, for general understanding on how wrong view leads to suffering
- bhava tanha, for specific understanding of wrong striving for defining a self
- the five skandhas, for right understanding of a wholesome alternative to defining a self
On the other hand, to prevent that our insights stays a mere theoretical product, we must also examine how these phenomena plays out in real life, with the aid of:
- right mindfulness, in order to recognize when we falsely identify with a certain concept of self
- right effort, to explore new habits allowing us to break the patterns creating more suffering, and to develop habits conducive to the cessation of suffering
I have always considered "my" limited view on meditation as the loss of self and a reconnection to the soul that connects us all. As such it isn't selfish, but a "coming home" into the spiritual haven that connects all things and can only be reached by achieving meditation and leaving the self - and its selfish amibitions - behind. And that is what gives us strength, it reconnects us, it replenishes us.
Of course, one might argue, that the result of a successful meditation is selfish as it helps the individual. But the connection to the "over soul" makes us feel more connected to all the other things in the world and that makes us a part of a larger community. Being refreshed in such a community is helpful for the entire community and thus not selfish.