Common sense is the basis for the other approaches. Science, philosophy and spirituality may try to move away from personal experiences but they all have roots in, and must start from common sense. As Reid pointed out, those who ignore the common-sense principles in building their metaphysics find their reductive constructions built upon sand, which makes reaching the conclusions that their own positions require impossible (Honderich 1995, p.142). Although science sometimes corrects the errors of common sense, even scientific theories ultimately depend on its support.
The other value of common sense is that it can deal with complex systems that are difficult to address adequately by using other approaches. Even with all the help of modern technology, science sometimes needs years to prove what is self-evident from the common sense perspective, and some phenomena may be so intricate that science or philosophy may never hope to achieve fully independent results and have to invoke a commonsensical evidential basis. Futurist Alvin Toffler (of ‘Future Shock’ fame) writes:
Where ‘hard data’ are available, of course, they ought to be taken into account. But where they are lacking, the responsible writer - even the scientist - has both a right and an obligation to rely on other kinds of evidence, including impressionistic or anecdotal data and the opinions of well-informed people (1970, p.15).
One simple example is that most of us have few difficulties accurately reading even subtle emotional states of others. After many years of research science is making some progress in this direction, but it is still far from being able to match the subtlety taken for granted in personal experiences.
Common sense has a huge practical value. Everyday life and human reactions are to a large extent based on personal experiences rather than scientific, spiritual or philosophical insights. Common sense does not rely on verbal interpretations, so it can be more direct and quicker. Such an intuitive grasp of a situation is often essential.
This approach can also guard against the extremes of the other ones. For instance, although reductionist science denies phenomena such as free will, the self and sometimes even the uniqueness of experience, ordinary life and language go on regardless, fully acknowledging them (e.g. every legal system is based on personal responsibility and hence, assumes the notion of free will). There is a sort of ‘bad faith’ among scientists, philosophers and those with spiritual inclinations who take for granted certain beliefs in day-to-day life, but deny the same in their practices.
- . Judge David Hodgson has written extensively on this topic (see, for example, Hodgson, 1994).