Another reason why the concept of Shiva and Shakti is so profound is that it is easily amenable to practical application. It was adopted by people throughout the ages because it facilitated powerful spiritual practices which could give an individual his own experience. This concept provides a base from which practices can be utilized to lead to union, communion with a power far greater than that of the individual. The system of Shiva and Shakti, the system of tantra throughout the world, leads to higher awareness, knowledge and beatitude.
An integral part of tantra is the use of sound in the form of mantras as a method of invoking higher forces. In English, mantras can be called incantations. Magic circles (mandalas and yantras) are also used. Both incantations and magic circles are an integral part of many universal systems, both old and new, and especially esoteric systems. And we can still see the remains of ancient magic circles used by ancient peoples. What is Stonehenge in Britain, but a cosmic magic circle? What are the Pyramids, but cosmic mandalas? The Mayan pyramids of Central America are surely mandalas, places for the invocation of higher vibrations. We could give thousands of examples, and they would all be rather obvious ones. There are millions of small seemingly insignificant magic circles that one would not normally look at twice and are so commonplace that they are not given any thought. For example, here in India almost every large tree has some form of altar as its base. Each and every one is a mandala, though more than likely the people who built them did not realize this.
To repeat: the essence of tantra is universal. It comes naturally to the psyche of man in general. It is not something that is imposed as are many other things in life. The essence of tantra comes naturally to man, even modern, city dwelling man, for though one can make superficial changes to one’s life, there are certain things that stir the very depths of one’s being. The essence of tantra is ingrained in the psyche of every man, as it has been in the peoples of bygone eras.