Summary: The Philosophy of No (page 2)
Bachelard takes the example of a scientific concept, that of mass, in order to identify the different types of epistemological explanation of it.
These different types of explanation reflect epistemological evolution, which is always moving in the direction of greater rational coherence.
The first explanation of the mass of an object is of the animistic type.
Reflecting a greedy
appreciation of reality, this considers that the biggest fruit is the best. As a result the notion of mass concretises the very desire to eat
1.
We therefore confuse mass with volume.
This initial unsatisfactory explanation is soon contradicted by experience. Now the first contradiction is, as always, the first knowledge
2.
This contradiction is that of the disproportion, in certain cases, of the "big" and the "heavy" (thus of volume and mass). The "fattest" is not necessarily the "richest". Bachelard gives the example of an empty shell. So there arises the concept of "intensity", a kind of "intimate richness" which causes the notion of mass to become internalized.
This first contradiction leads the scientific mind to go beyond the visual aspect of an object (its volume) to estimate its mass. An instrument must be found to establish this more objectively: the balance. The mind then enters a second stage: empiricism (or realism).
To this simple and positive concept corresponds a solid, clear, positive, immobile
3 empirical thought. We think the problem has been solved:
Such empirical thinking attached to such peremptory experience receives the name of realist thinking 4.
However, it is not so simple. Empiricism in fact uses the instrument (the balance), before knowing the theory (the principle of the lever)
It is in the next stage, that of rationalism, that the notion of mass becomes more complex. With Newton's classical mechanics, we discover that we must define this notion in relation to others: The notion of mass is then defined in a system of notions and no longer just as a primitive element of immediate and direct experience
5.
The mass of an object is in fact defined by the ratio of its force and acceleration.
These three notions are established correlatively in a clearly rational relationship since this relationship is perfectly analysed by the rational laws of arithmetic.
From the realistic point of view, these notions are very diverse, so bringing them together in the same formula is factitious.
However, rationalism goes beyond itself, and we reach what Bachelard calls complete rationalism, complex rationalism, when we discover that mass is dependent on speed: The mass of an object is therefore relative to the displacement of that object
6. This essential contribution of Einstein's principle of relativity leads us to understand that the notion of absolute mass is meaningless.
Here again we see a complication of the notion of mass. This initially simple notion gives way to a complex one.
This complexity becomes total (in the sense that it is no longer intuitively comprehensible), in the final stage, which Bachelard calls dialectical rationalism, or surrationalism.
With regard to the concept of mass, we reach this final stage with Dirac, who shows that there are two masses for a single object. The first is mass as understood by previous philosophies, from realism to complex rationalism. Although each of these epistemological approaches characterised it differently, they all took it as their object. But Dirac shows that the second mass of an object is a negative mass!
While one half of Dirac's mechanics recovers and extends classical and relativistic mechanics, the other half gives rise to a dialectic.
For a 19th century scientist, the concept of negative mass is monstrous
7. For us too, who often remain caught up in the realist conception of mass:
We, like everyone else, have our hours of realism and even about a concept as educated as the concept of mass, we are not fully psychoanalysed 8.
1 chap.1, p.22
2 ibid.
3 chap.1, p.26
4 ibid., p.27
5 ibid.
6 ibid., p. 31
7 ibid., p.37
8 chap.2, p.45