Mind, New Series, Vol. 49, No. 196. (Oct., 1940), pp. 403-426.
Dialectic is a theory which maintains that human thought develops in a way characterised by the so-called dialectic triad: thesis, anti-thesis and synthesis. The last one aims to develop a solution of the struggle between the thesis and anti-thesis, and obtained a new dialectic triad or stop with a particular synthesis reached. To the dialecticians when a theory under consideration has been refuted, there will probably have something in it creditable of being preserved. And this feature will be enriched by the adherents of the anti-thesis. Thus a satisfactory solution of the struggle will be only a synthesis, i.e, a theory in which the best points of both thesis and anti-thesis are preserved.
According to the author we have to be very careful not to admit to much from the dialectic viewpoint, because for example it says that the thesis ‘produces’ its anti-thesis. Actually, it is only our critical attitude which produces the anti-thesis. Similarly, we have to be careful not to think that a struggle between a thesis and its anti-thesis will always ‘produce’ a synthesis; the synthesis usually will be much more than a construction built merely of material supplied by thesis and anti-thesis. Another important point to be chary is the way in which dialecticians speak about contradictions. For them there is only one way of criticising a given theory: to show that either it is self-contradictory, or it is contradicted by some other accepted statements. But a theory which involves a contradiction is entirely useless, because it does not convey any sort information.
To Karl Popper the method used in the development of human though in general, can be described as a certain kind of trial and error method. We can assume a position against a theory (hold or reject). Only when a certain theory or system is dogmatically maintained throughout some longer period it does not occur. If the method of trial and error is developed more and more consciously, then it begins to take on the characteristics features of scientific method. This method can briefly be described thus:
· Tentatively sort of solution (a theory)
· Criticise (to look for vulnerable points, with an examination brutal as possible) and test the theory in question
If the outcome of a test shows that the theory is erroneous, then it is eliminated. Its success depends mainly on three conditions, namely, that sufficiently may and sufficiently different theories are offered, and that sufficiently severe tests are made. When a theory is rejected, this induces the humans to look out for a new standpoint, which is finally what lets the development of the knowledge.