The attainment of samadhi
The place of samadhi
The difference between thinking with and without samadhi is like the difference between the footprints of an elephant and that of a mouse. Only with samadhi is there the penetration, the open-mindedness and the clarity of memory necessary for great mental attainment.
The attainment of samadhi comes in degrees. Anyone who has experienced "altered states of consciousness" has experienced some degree of samadhi. Samadhi can be attained by concentrating on any object at all, provided you have enough desire or need of samadhi. If you are already happy and content with your life there is little hope you will generate the deep longing necessary to achieve samadhi.
Religious people of many faiths wrongly interpret the experience of samadhi in prayer or meditation as "God presence", or "religious experience", when it is merely the bliss of a still mind. Their lack of wisdom guarantees their spiritual bankruptcy. Without wisdom, samadhi is useless. Faith alone can still a racing mind, but only faith in Reality will Enlighten it.
So, samadhi is essential, yet the object of samadhi can so easily be a pitfall. Then what is a safe object for samadhi? The wise direct their minds towards Truth itself. The beginner experiments with his mind in preparation for greater things. The fool merely directs his mind away from his problems.