In this week's Parasha, Parashat Yisro, G-d gives the Torah to the Jewish People on Mount Sinai.
Standing at the foot of Mount Sinai in readiness to receive the Torah, the Jewish people proclaimed that they would first observe all its commandments and subsequently attempt to understand them. They declared first "we will do" and then "we will understand."
Some people maintain that they will begin to observe mitzvot when they understand them.
The irrationality of this attitude may be understood from the example of the body. The body requires a daily intake of food and air. No amount of thinking, speaking or studying about food and nutrition can substitute for actual consumption. On the contrary, failure to eat or breathe will even weaken the person.
Obviously the correct and healthy approach is not to study nutrition and respiration first, and then practice them, but the reverse. And while the person is eating and drinking and breathing -- though he may not fully understand the process involved -- he is strengthened.
The same applies to the soul. The elements which it requires for sustenance are best known to its Creator - G-d. At Mount Sinai He informed us that the "air" and "food" vital to our spiritual existence are -- Torah and mitzvot.