The clear thinking of the young Rudolf Steiner identifies the relevant elements from a mass of thoughts about atomistic concepts and finds (in 1882) that the atom is seen as the only principle of reality. It underlies all material and sensual qualities, but has no qualities itself. It is not spatial and is undefined; it is just 'something', and this something is the foundation and essence of all being. As soon as one would assign a characteristic to it, it could not be the foundation any longer. So it has to be an uncharacteristic ‘something’. And still, atoms also cannot be only a concept, they have to exist in reality. The atom has to be something special, but in a general way.
Rudolf Steiner acknowledges the possibility that the concept of the atom could be used as a thought-model. But the problem is that it is considered to be the only real thing in the world, being the constituting element of it. So it is not only a thought that can be skillfully used, it is reality per se.
And then Rudolf Steiner goes on:
'If someone wanted to speak of the harmlessness of the atomistic notions, one could, to refute him, go ahead and hold up to him the consequences that have been derived from them. There are especially two necessary consequences: firstly, that the predicate of original existence is squandered on isolated substances void of spirit, quite indifferent toward one another, and otherwise wholly undefined, in whose interaction only mechanical necessity rules, so that the entire remainder of the world of phenomena exists as their empty haze, and has mere chance to thank for its existence; secondly, insurmountable limits to our recognizing result from this. For the human mind, the concept of the atom is, as we have shown, something completely empty, the mere “Something.” But since the atomists cannot be content with this content, but call for actual substance, yet determine this substance in a way in which it can nowhere be given, they must proclaim the unrecognizability of the actual essential being of the atom.
'Concerning the other limit of knowledge, the following is to be noted. If one sees thinking too as a function of the interaction of complexes of atoms, which remain indifferent toward one another, it is not at all to be marveled at, why the connection between movement of the atoms on the one hand, and thinking and sensation on the other, is not to be comprehended, which atomism therefore sees as a limit of our recognition. There is something to comprehend only where a conceptual passage over exists. But if one first so limits the concepts that in the sphere of the one, nothing is to be found that would make possible the passage to the sphere of the other, then comprehending is excluded from the start. Moreover, this passage would indeed have to be not of a merely speculative nature, but rather it would have to be a real process, thus permitting of being demonstrated. But this is again prevented by the non-sensoriness of atomistic motion.
‘With the giving up of the concept of the atom, these speculations about the limit of our knowledge fall away by themselves. From nothing must one guard oneself more than from such determinations of boundary, for beyond the boundary there is then room for everything possible. The most irrational spiritism, as well as the most nonsensical dogma, could hide behind such assumptions. The same are quite easy to refute in every single case, by showing that at their foundation there always lies the mistake of seeing a mere abstraction for more than it is, or holding merely relative concepts to be absolute ones, and similar errors. A large number of false notions has come into circulation especially through the incorrect concepts of space and time.’The true face of the atom