Then, in 2000, Danah Zohar and Ian Marshall (2) suggested that there is a third type of intelligence – spiritual intelligence or SQ – which is also vital to successful living. SQ relates to fundamental issues of life, such as meaning and value, or questions of good and evil. It is associated with qualities such as inspiration by vision and values, flexibility, self-awareness, the capacity to face and use pain and suffering, a reluctance to cause unnecessary harm, seeing the connections between diverse things, seeking deep answers to ‘why …?’ or ‘what …?’, and the ability to go against convention.

All these types of intelligence depend in one way or another on the body, thus forming an interactive whole. For instance, our brains are nourished and energised by our whole bodies, and our thoughts affect our bodies in many ways; we feel emotions in our bodies and they affect its health; conversely, the health of our bodies affects our feelings and the quality of our thoughts; and SQ can be enhanced by mind-body techniques such as meditation. Indeed, the realisation is growing that many organs of the body, maybe even all cells, are engaged in the processes of thinking and decision-making in various ways.

Finally, systems sciences, particularly ecology, have made us aware that ‘No man is an island.’ We are all parts of the whole and the idea of the isolated individual that dominated twentieth century western thought is a mirage. Without the planet’s ecosystems to provide food, water and air we would not exist. Without the solar system, and the galaxy and universe beyond, those supporting ecosystems would not exist. And so we are inextricably parts of the whole. In a similar way, our personas and psyches with which we identify so closely are largely creations of the families and societies in which we grew up. So learning to live in creative, constructive relationships with other people and the natural world as integral parts of the whole is an essential aspect of becoming a mature human.