Profound implications of the heuristic way
The proven success of the heuristic method, in all the areas where it has so far been used, has implications far more profound than is usually appreciated.
'Static' and 'dynamic' truth
By far the most important implication is the change which has come about in our understanding of the nature of knowledge itself.
To use an analogy, if you believe that the way to knowledge that you are using is able to deliver certainties, then you will see the quest for knowledge as a kind of walk along a path. Eventually, you may arrive at your destination. Then you are entitled to sit down and make no further efforts. Each truth that you discover is the final destination of that particular walk, and there is nowhere further to go.
By contrast, the heuristic way to knowledge entails a new meaning of 'truth'—exchanging a dynamic conception for a static one. The search for knowledge is still a journey, but it is more like climbing a cliff face. When you make a discovery, it is like finding a hold on the cliff face that you are climbing up—you test it carefully and thoroughly to make sure that it will bear your weight for the present, and then you use it as a hold while you are looking for the next hold. Then, no sooner have you found that next hold, than you test that one carefully and thoroughly, and move on up to it. The first hold can then either be kept for future use, or else it can be entirely abandoned, and you do not then really care if it crumbles away. You have no further need of it.
This is what we mean by the maxim that there are "no eternal truths". No hold is ever high enough up the cliff face to be a sufficient reason to give up climbing altogether. The heuristic way always involves looking for a hold that is higher up. The maxim is about the concept of truth itself, not about the existence, or not, of a particular kind of proposition.
Ethics of belief
The way to establish that a particular hold is strong enough to bear your weight is to test it vigorously before trusting it. So using a particular hold—believing a particular proposition—depends upon having already done the work of testing it properly.
This lays the foundation of an ethic of knowledge, in which believing in a proposition carries with it the obligation to have done the work of searching for negative instances. In such an ethic, it is a sin to believe in excess of the work done, and it is always your duty to look further up the cliff face for new holds. But you are not looking for a final resting place, so the work at any stage only has to be thorough enough to establish a hold which will bear your weight while you look around for the next higher hold.
A heuristic culture
Such an ethic opens the way to a knowledge-based culture, in which no assertions whatever are simply plucked out of thin air, or accepted as self-evident. There are no arbitrary assumptions. Every proposition which is ever believed, or used in any sort of knowledge structure, is continuously, and unendingly, tested for its correspondence with reality.
In a totally knowledge-based culture this would apply to individuals' personal lives, as well as to the design and management of social institutions.
A totally heuristic way of life would mean that you never postulate statically. You always propose ways of unendingly testing the postulate, as long as you hold it, and you never believe anything more than is justified by the work you have done on it.
Giving up certainty is a sign of maturity
All these are signs of intellectual and emotional maturity.
One could go into the psychology of the human need for certainty. It is probably connected with the baby's need for security, and the childish need to be able to rely on parental authority.
The abandonment of the search for certainty was a giant leap for mankind. It represented a growing up. To be comfortable with the abandonment of belief in eternal truth is a sign of childhood's end, both for an individual, and for a culture.
What if some questions cannot be solved?
It is necessary to ask whether there are any questions that cannot ever be solved by a heuristic method. How do we know whether or not such questions exist and how shall we deal with them if we seem to meet them?
This matter will inevitably be argued about at length but, within a heuristic culture, the answer will be likely to have the logical structure indicated by Hans Reichenbach, with his parable of the fisherman:
"a fisherman … casts a net into an unknown part of the ocean — he does not know whether he will catch fish, but he knows that if he wants to catch fish he has to cast his net. … we do not know whether we shall have a good catch, but we try, at least, and try by the help of the best means available."
Reichenbach, H. (1951) The Rise of Scientific Philosophy. Berkeley, Calif.: University of California Press.