Zen and many other nondualist traditions caution against excessive emphasis on thought and against confusing concepts with the realities that they are meant to represent. However, we should not take this to mean that all thought should be erased from our minds and that we should strive for a state of vegetable-like quietude.
First of all, such a state of permanent mental silence is unattainable; our brains are thought-forming machines and evolution has selected for more complexly developed prefrontal cortexes so that we can use thought to best handle our environment. As a result, some thought will always arise when there is an environmental demand for it. Instead of making war on thoughts, it would therefore, seem wiser to make peace with them.
Second of all, thoughts are incredibly useful in daily life; it helps to think about what time one’s bus comes, which ingredients in one’s breakfast best work together, what to say to one’s boss when one needs to address a work problem, and many other such things. In situations like these, thought is a great help.
Finally, for those of us with an interest in the sciences, thought is an indispensable tool. This does not mean that we should again fall prey to the trap of confusing concepts with realities, but it does mean that we can use thought to understand some amazing aspects of nature. Understanding the Doppler Effect, for instance, allows one to simultaneously understand why ambulance sirens seem to shift into a higher pitch as they approach us and a lower pitch as they speed away from us and how we know that we live in an expanding universe. In this way, some scientific thought can deepen our perception and enrich our experience of the world.
Even though thought has these and many other special values for us, however, we would do well to see concepts as concepts when we are using them and to take time to rest in (and as) that nondual reality before which all words and concepts falter. When we abide in the nondual realm, silence is the language of choice. Indeed, after having rested in this realm for some time, we can return to the world of daily life with all of its distinctions with a deeper understanding of their nondual nature. We learn to appreciate distinctness without falling prey to the illusion of separation and to think without getting ensnared by thought. In this way, we learn to use the net of thought to catch useful insights and applications and not to be caught up in it.